fix(security): resolve CodeQL warnings (#380)

Author: Nuzair46

lib/config/integrations/heroku.rb

@@ -26,7 +26,7 @@ def vars
       end
 
       def environment
-        heroku("run 'echo $RAILS_ENV'").chomp[/(\w+)\z/]
+        heroku("run 'echo $RAILS_ENV'").chomp[/(?>\w+)\z/]
       end
 
       def heroku(command)

lib/config/options.rb

@@ -150,7 +150,7 @@ def has_key?(key)
     end
 
     def method_missing(method_name, *args)
-      if Config.fail_on_missing && method_name !~ /.*(?==\z)/m
+      if Config.fail_on_missing && !method_name.to_s.end_with?('=')
         raise KeyError, "key not found: #{method_name.inspect}" unless key?(method_name)
       end
       super