(maint) Pin puppet-module-gems

Pin puppet-module-posix-system and puppet-module-win-system to an older
version since the newer ones do not bundle some gems that we use in
acceptance (i.e. beaker-module_install_helper), causing tests to fail.

Author: GabrielNagy

Gemfile

@@ -37,9 +37,10 @@ group :development do
   gem "puppet-strings",                                          require: false
   gem "github_changelog_generator",                              require: false, git: 'https://github.com/skywinder/github-changelog-generator', ref: '20ee04ba1234e9e83eb2ffb5056e23d641c7a018' if Gem::Version.new(RUBY_VERSION.dup) >= Gem::Version.new('2.2.2')
 end
+
 group :system_tests do
-  gem "puppet-module-posix-system-r#{minor_version}",                            require: false, platforms: [:ruby]
-  gem "puppet-module-win-system-r#{minor_version}",                              require: false, platforms: [:mswin, :mingw, :x64_mingw]
+  gem "puppet-module-posix-system-r#{minor_version}", '~> 0.5',                  require: false, platforms: [:ruby]
+  gem "puppet-module-win-system-r#{minor_version}", '~> 0.5',                    require: false, platforms: [:mswin, :mingw, :x64_mingw]
   gem "beaker", *location_for(ENV['BEAKER_VERSION'] || '~> 4')
   gem "beaker-abs", *location_for(ENV['BEAKER_ABS_VERSION'] || '~> 0.5')
   gem "beaker-pe",                                                               require: false