Change `TargetRubyVersion` to 2.0 in order to check the RuboCop project
Change `TargetRubyVersion` to 2.0 in order to check the RuboCop project

RuboCop supports Ruby 2.0. https://github.com/bbatsov/rubocop/blob/master/rubocop.gemspec#L11
So, `TargetRubyVersion` should be `2.0`.

jonas054/rubocop,jonas054/rubocop