(puppetlabs#301) Make code work in Ruby 2.3.0

In 08936f9 ("(MAINT) Rubocop: Fix
Performance/RegexpMatch"), a few Regexp matches were switched from `=~`
to `.match?`. Unfortuantely, `.match?` [wasn’t introduced until Ruby
2.4.6][match?], so that broke Ruby 2.3.0 compatibility.

This reverts that commit and disables the relevant rubocop check.

[match?]: https://apidock.com/ruby/String/match%3F

Author: danielparks

.rubocop.yml

@@ -599,3 +599,7 @@ Style/HashTransformValues:
 Naming/MethodParameterName:
   Enabled: true
   AllowedNames: [ o ]
+
+# match? was added in Ruby 2.4.6
+Performance/RegexpMatch:
+  Enabled: false

Rakefile

@@ -56,7 +56,7 @@ PuppetLint.configuration.ignore_paths = %w(acceptance/**/*.pp spec/**/*.pp pkg/*
 desc 'Validate Ruby source files and ERB templates.'
 task :validate do
   Dir['spec/**/*.rb','lib/**/*.rb'].each do |ruby_file|
-    sh "ruby -c #{ruby_file}" unless /spec\/fixtures/.match?(ruby_file)
+    sh "ruby -c #{ruby_file}" unless ruby_file =~ /spec\/fixtures/
   end
   Dir['lib/puppet-strings/yard/templates/**/*.erb'].each do |template|
     sh "erb -P -x -T '-' #{template} | ruby -c"

lib/puppet-strings/markdown/function.rb

@@ -21,11 +21,11 @@ def render
 
     def type
       t = @registry[:type]
-      if /ruby4x/.match?(t)
+      if t =~ /ruby4x/
         "Ruby 4.x API"
-      elsif /ruby3/.match?(t)
+      elsif t =~ /ruby3/
         "Ruby 3.x API"
-      elsif /ruby/.match?(t)
+      elsif t =~ /ruby/
         "Ruby"
       else
         "Puppet Language"

lib/puppet/face/strings.rb

@@ -148,7 +148,7 @@
   def check_required_features
     raise RuntimeError, "The 'yard' gem must be installed in order to use this face." unless Puppet.features.yard?
     raise RuntimeError, "The 'rgen' gem must be installed in order to use this face." unless Puppet.features.rgen?
-    raise RuntimeError, 'This face requires Ruby 1.9 or greater.' if RUBY_VERSION.match?(/^1\.8/)
+    raise RuntimeError, 'This face requires Ruby 1.9 or greater.' if RUBY_VERSION =~ /^1\.8/
   end
 
   # Builds the options to PuppetStrings.generate.