* post message at-mention profile pop-over
* remove hover effect to special mentions
* make non-clickable the non-existing at-mention username
* fix "video call" position
* use usernameMap instead of initially defined liteUsernameMap
* update per comments
This migrates the existing webapp tests to using Jest and Enzyme. The
infrastructure is put in place for React component testing, and a few
simple example component tests are implemented.
This also adds snapshot testing of components, coverage checking for the
webapp (although that is not yet integrated to Coveralls), and the
ability to run npm run test:watch to automatically re-run affected tests
when working on the webapp codebase.
