* WIP - initial exploration into post mentioon autocomplete
* replace the autosize textarea with mention autocomplete, adjusting height
* add cypress tests for mentioning in a post
* fix resizing of text areas
* refactor text area resize hook
* refactoring
* update cypress tests
* remove mergeRefs from utils, extract UserListItemContent
* allow useTextAreaAutoResize elements to have height greater than minimum, apply styles to container
* Trigger Travis CI
* Travis plz
* small refactors
* add comments and constants as per PR feedback
Co-authored-by: Nick Taylor <nick@dev.to>
