bracket-push: rename to matching-brackets (#298)

* bracket-push: rename to matching-brackets

This rename was proposed in:
exercism/problem-specifications#1501

The rationale for the name is:

* to name the exercise by its story, not by what it potentially teaches
* to avoid unnecessarily biasing the solution space

* 👀 rename reference in settings.gradle

Author: SleeplessByte

config.json

@@ -513,7 +513,7 @@
       ]
     },
     {
-      "slug": "bracket-push",
+      "slug": "matching-brackets",
       "uuid": "cbbbd7db-224f-45ca-a108-4dc6bc98e4a0",
       "core": false,
       "unlocked_by": "flatten-array",

exercises/bracket-push/.meta/src/reference/kotlin/BracketPush.kt renamed to exercises/matching-brackets/.meta/src/reference/kotlin/MatchingBrackets.kt

@@ -1,7 +1,7 @@
 import java.util.*
 import java.util.Collections.asLifoQueue
 
-object BracketPush {
+object MatchingBrackets {
 
     private val CLOSING_TO_OPENING_MAP = mapOf(
              '}' to '{',

exercises/bracket-push/.meta/version renamed to exercises/matching-brackets/.meta/version

@@ -1,4 +1,4 @@
-# Bracket Push
+# Matching Brackets
 
 Given a string containing brackets `[]`, braces `{}`, parentheses `()`,
 or any combination thereof, verify that any and all pairs are matched