remove typo

Author: Lucca Kaiser

mysql_blob_streaming.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.license = 'MIT'
 
   spec.add_dependency "mysql2", ">= 0.5.5"
-  spec.required_ruby_version = "">= 2.0.0"
+  spec.required_ruby_version = ">= 2.0.0"
 
   spec.files = Dir["lib/**/*.rb", "ext/**/*.{c,h,rb}", "README.markdown"]
   spec.extensions = ['ext/mysql_blob_streaming/extconf.rb']