Update Rubocop config for current Rubocop

Running Rubocop printed out a huge number of new warnings and errors. For the most part, I just silenced them since this gem has been pretty stable and I assume you don't want to modify things just to match newer recommendations. I did add `required_ruby_version` to the gemspec, though, since that just seems like a good idea. It's set to 2.3.0, based on the GitHub Actions CI job.

.rubocop.yml

@@ -1,6 +1,9 @@
 require:
   - rubocop-performance
 
+AllCops:
+  TargetRubyVersion: 2.3
+
 Layout/SpaceAroundEqualsInParameterDefault:
   EnforcedStyle: no_space
 
@@ -12,3 +15,378 @@ Style/SafeNavigation:
 
 Style/NegatedIf:
   Enabled: false
+
+Metrics/MethodLength:
+  Max: 20
+
+Style/OptionalBooleanParameter:
+  Enabled: false
+
+Style/SpecialGlobalVars:
+  Enabled: false
+
+Gemspec/DeprecatedAttributeAssignment: # new in 1.30
+  Enabled: false
+
+Gemspec/DevelopmentDependencies: # new in 1.44
+  Enabled: false
+
+Gemspec/RequireMFA: # new in 1.23
+  Enabled: false
+
+Layout/LineContinuationLeadingSpace: # new in 1.31
+  Enabled: false
+
+Layout/LineContinuationSpacing: # new in 1.31
+  Enabled: false
+
+Layout/LineEndStringConcatenationIndentation: # new in 1.18
+  Enabled: false
+
+Layout/SpaceBeforeBrackets: # new in 1.7
+  Enabled: false
+
+Lint/AmbiguousAssignment: # new in 1.7
+  Enabled: false
+
+Lint/AmbiguousOperatorPrecedence: # new in 1.21
+  Enabled: false
+
+Lint/AmbiguousRange: # new in 1.19
+  Enabled: false
+
+Lint/ConstantOverwrittenInRescue: # new in 1.31
+  Enabled: false
+
+Lint/DeprecatedConstants: # new in 1.8
+  Enabled: false
+
+Lint/DuplicateBranch: # new in 1.3
+  Enabled: false
+
+Lint/DuplicateMagicComment: # new in 1.37
+  Enabled: false
+
+Lint/DuplicateMatchPattern: # new in 1.50
+  Enabled: false
+
+Lint/DuplicateRegexpCharacterClassElement: # new in 1.1
+  Enabled: false
+
+Lint/EmptyBlock: # new in 1.1
+  Enabled: false
+
+Lint/EmptyClass: # new in 1.3
+  Enabled: false
+
+Lint/EmptyInPattern: # new in 1.16
+  Enabled: false
+
+Lint/IncompatibleIoSelectWithFiberScheduler: # new in 1.21
+  Enabled: false
+
+Lint/ItWithoutArgumentsInBlock: # new in 1.59
+  Enabled: false
+
+Lint/LambdaWithoutLiteralBlock: # new in 1.8
+  Enabled: false
+
+Lint/LiteralAssignmentInCondition: # new in 1.58
+  Enabled: false
+
+Lint/MixedCaseRange: # new in 1.53
+  Enabled: false
+
+Lint/NoReturnInBeginEndBlocks: # new in 1.2
+  Enabled: false
+
+Lint/NonAtomicFileOperation: # new in 1.31
+  Enabled: false
+
+Lint/NumberedParameterAssignment: # new in 1.9
+  Enabled: false
+
+Lint/OrAssignmentToConstant: # new in 1.9
+  Enabled: false
+
+Lint/RedundantDirGlobSort: # new in 1.8
+  Enabled: false
+
+Lint/RedundantRegexpQuantifiers: # new in 1.53
+  Enabled: false
+
+Lint/RefinementImportMethods: # new in 1.27
+  Enabled: false
+
+Lint/RequireRangeParentheses: # new in 1.32
+  Enabled: false
+
+Lint/RequireRelativeSelfPath: # new in 1.22
+  Enabled: false
+
+Lint/SymbolConversion: # new in 1.9
+  Enabled: false
+
+Lint/ToEnumArguments: # new in 1.1
+  Enabled: false
+
+Lint/TripleQuotes: # new in 1.9
+  Enabled: false
+
+Lint/UnexpectedBlockArity: # new in 1.5
+  Enabled: false
+
+Lint/UnmodifiedReduceAccumulator: # new in 1.1
+  Enabled: false
+
+Lint/UselessRescue: # new in 1.43
+  Enabled: false
+
+Lint/UselessRuby2Keywords: # new in 1.23
+  Enabled: false
+
+Metrics/CollectionLiteralLength: # new in 1.47
+  Enabled: false
+
+Naming/BlockForwarding: # new in 1.24
+  Enabled: false
+
+Security/CompoundHash: # new in 1.28
+  Enabled: false
+
+Security/IoMethods: # new in 1.22
+  Enabled: false
+
+Style/ArgumentsForwarding: # new in 1.1
+  Enabled: false
+
+Style/ArrayIntersect: # new in 1.40
+  Enabled: false
+
+Style/CollectionCompact: # new in 1.2
+  Enabled: false
+
+Style/ComparableClamp: # new in 1.44
+  Enabled: false
+
+Style/ConcatArrayLiterals: # new in 1.41
+  Enabled: false
+
+Style/DataInheritance: # new in 1.49
+  Enabled: false
+
+Style/DirEmpty: # new in 1.48
+  Enabled: false
+
+Style/DocumentDynamicEvalDefinition: # new in 1.1
+  Enabled: false
+
+Style/EmptyHeredoc: # new in 1.32
+  Enabled: false
+
+Style/EndlessMethod: # new in 1.8
+  Enabled: false
+
+Style/EnvHome: # new in 1.29
+  Enabled: false
+
+Style/ExactRegexpMatch: # new in 1.51
+  Enabled: false
+
+Style/FetchEnvVar: # new in 1.28
+  Enabled: false
+
+Style/FileEmpty: # new in 1.48
+  Enabled: false
+
+Style/FileRead: # new in 1.24
+  Enabled: false
+
+Style/FileWrite: # new in 1.24
+  Enabled: false
+
+Style/HashConversion: # new in 1.10
+  Enabled: false
+
+Style/HashExcept: # new in 1.7
+  Enabled: false
+
+Style/IfWithBooleanLiteralBranches: # new in 1.9
+  Enabled: false
+
+Style/InPatternThen: # new in 1.16
+  Enabled: false
+
+Style/MagicCommentFormat: # new in 1.35
+  Enabled: false
+
+Style/MapCompactWithConditionalBlock: # new in 1.30
+  Enabled: false
+
+Style/MapIntoArray: # new in 1.63
+  Enabled: false
+
+Style/MapToHash: # new in 1.24
+  Enabled: false
+
+Style/MapToSet: # new in 1.42
+  Enabled: false
+
+Style/MinMaxComparison: # new in 1.42
+  Enabled: false
+
+Style/MultilineInPatternThen: # new in 1.16
+  Enabled: false
+
+Style/NegatedIfElseCondition: # new in 1.2
+  Enabled: false
+
+Style/NestedFileDirname: # new in 1.26
+  Enabled: false
+
+Style/NilLambda: # new in 1.3
+  Enabled: false
+
+Style/NumberedParameters: # new in 1.22
+  Enabled: false
+
+Style/NumberedParametersLimit: # new in 1.22
+  Enabled: false
+
+Style/ObjectThen: # new in 1.28
+  Enabled: false
+
+Style/OpenStructUse: # new in 1.23
+  Enabled: false
+
+Style/OperatorMethodCall: # new in 1.37
+  Enabled: false
+
+Style/QuotedSymbols: # new in 1.16
+  Enabled: false
+
+Style/RedundantArgument: # new in 1.4
+  Enabled: false
+
+Style/RedundantArrayConstructor: # new in 1.52
+  Enabled: false
+
+Style/RedundantConstantBase: # new in 1.40
+  Enabled: false
+
+Style/RedundantCurrentDirectoryInPath: # new in 1.53
+  Enabled: false
+
+Style/RedundantDoubleSplatHashBraces: # new in 1.41
+  Enabled: false
+
+Style/RedundantEach: # new in 1.38
+  Enabled: false
+
+Style/RedundantFilterChain: # new in 1.52
+  Enabled: false
+
+Style/RedundantHeredocDelimiterQuotes: # new in 1.45
+  Enabled: false
+
+Style/RedundantInitialize: # new in 1.27
+  Enabled: false
+
+Style/RedundantLineContinuation: # new in 1.49
+  Enabled: false
+
+Style/RedundantRegexpArgument: # new in 1.53
+  Enabled: false
+
+Style/RedundantRegexpConstructor: # new in 1.52
+  Enabled: false
+
+Style/RedundantSelfAssignmentBranch: # new in 1.19
+  Enabled: false
+
+Style/RedundantStringEscape: # new in 1.37
+  Enabled: false
+
+Style/ReturnNilInPredicateMethodDefinition: # new in 1.53
+  Enabled: false
+
+Style/SelectByRegexp: # new in 1.22
+  Enabled: false
+
+Style/SendWithLiteralMethodName: # new in 1.64
+  Enabled: false
+
+Style/SingleLineDoEndBlock: # new in 1.57
+  Enabled: false
+
+Style/StringChars: # new in 1.12
+  Enabled: false
+
+Style/SuperArguments: # new in 1.64
+  Enabled: false
+
+Style/SuperWithArgsParentheses: # new in 1.58
+  Enabled: false
+
+Style/SwapValues: # new in 1.1
+  Enabled: false
+
+Style/YAMLFileRead: # new in 1.53
+  Enabled: false
+
+Performance/AncestorsInclude: # new in 1.7
+  Enabled: false
+
+Performance/BigDecimalWithNumericArgument: # new in 1.7
+  Enabled: false
+
+Performance/BlockGivenWithExplicitBlock: # new in 1.9
+  Enabled: false
+
+Performance/CollectionLiteralInLoop: # new in 1.8
+  Enabled: false
+
+Performance/ConcurrentMonotonicTime: # new in 1.12
+  Enabled: false
+
+Performance/ConstantRegexp: # new in 1.9
+  Enabled: false
+
+Performance/MapCompact: # new in 1.11
+  Enabled: false
+
+Performance/MapMethodChain: # new in 1.19
+  Enabled: false
+
+Performance/MethodObjectAsBlock: # new in 1.9
+  Enabled: false
+
+Performance/RedundantEqualityComparisonBlock: # new in 1.10
+  Enabled: false
+
+Performance/RedundantSortBlock: # new in 1.7
+  Enabled: false
+
+Performance/RedundantSplitRegexpArgument: # new in 1.10
+  Enabled: false
+
+Performance/RedundantStringChars: # new in 1.7
+  Enabled: false
+
+Performance/ReverseFirst: # new in 1.7
+  Enabled: false
+
+Performance/SortReverse: # new in 1.7
+  Enabled: false
+
+Performance/Squeeze: # new in 1.7
+  Enabled: false
+
+Performance/StringIdentifierArgument: # new in 1.13
+  Enabled: false
+
+Performance/StringInclude: # new in 1.7
+  Enabled: false
+
+Performance/Sum: # new in 1.8
+  Enabled: false

sd_notify.gemspec

@@ -11,6 +11,7 @@ Gem::Specification.new do |s|
   s.files       = ["lib/sd_notify.rb", "LICENSE", "README.md", "CHANGELOG.md"]
   s.homepage    = "https://github.com/agis/ruby-sdnotify"
   s.license     = "MIT"
+  s.required_ruby_version = ">= 2.3.0"
 
   s.add_development_dependency "minitest"
   s.add_development_dependency "rubocop"