Use MultiJson everywhere and remove `.to_json` that requires rails.

https://gitlab.com/gitlab-org/packagecloud-ruby/blob/master/lib/packagecloud/client.rb#L86 is not standard library. The method is monkey patched by rails: http://apidock.com/rails/Hash/to_json.

I don't understand how this doesn't break during the test, but if you try to load the gem in IRB it fails:

irb(main)> client.create_repository('new-secret-repo', true)

NoMethodError: undefined method `to_json' for {"repository"=>{"name"=>"new-secret-repo", "private"=>"1"}}:Hash

changed title from Use MultiJson everywhere and remove ".to_json" that requires rails. to Use MultiJson everywhere and remove {+.to_json+} that requires rails.

assigned to @brodock

mentioned in merge request !2 (merged)

closed via merge request !2 (merged)

closed via commit 5f59593e