Plugin gives warnings in javascript console - needs minor update for api change

[nikkilocke]

When I use your great retort plugin with the latest Discourse, I get javascript console warnings:

be @ plugin-api.js:19
plugin-api.js:19 [PLUGIN retort] To prevent errors in tests, add a `pluginId` key to your `modifyClass` call. This will ensure the modification is only applied once.

Is there any chance you could fix this? I imagine it would be quite easy to fix, and might prevent problems in the future.