Issues with the tests on DmpEditor

[andrewebdev]

I was having issues with the DmpEditor tests. This might be related to how ReMirror works. Adding this issue as a reminder that we need to properly fix the tests for this.

[jupiter007]

I just wanted to make a note in this ticket about the updates I made to get around the 500 error I was seeing when loading the styleguide. I think it's an issue with Remirror and NextJS not playing nicely together so the change is a work around: #115