add default ignored gem list

Author: markburns

lib/problematic_variable_finder/DEFAULT_IGNORED_GEMS

@@ -0,0 +1,13 @@
+actioncable
+actionmailbox
+actionmailer
+actionpack
+actiontext
+actionview
+activejob
+activemodel
+activerecord
+activeresource
+activestorage
+activesupport
+rails

lib/problematic_variable_finder/gem_problems.rb

@@ -47,9 +47,14 @@ def in_only_gem_list?(name)
     end
 
     def ignore_gem?(name) 
+      return true if ignore_list.include?(name)
       options[:ignore] && Array(options[:ignore]).include?(name)
     end
 
+    def ignore_list
+      @ignore_list ||= ProblematicVariableFinder.read_file(File.expand_path('DEFAULT_IGNORED_GEMS', __dir__)).map(&:strip)
+    end
+
     def outdated_gems 
       @outdated_gems ||= outdated.map{|o| o.gsub(/\s+\*\s+/, '').split(" ").first }
     end