* Fix flaky redis tests * Add a random integer helper for tests
* Fix flaky tests that require redis which were occasionally failing
* Format Javascript and CSS files with `prettier`: `prettier --write 'CTFd/themes/**/*'` * Format Python with `black`: `black CTFd` & `black tests` * Travis now uses xenial instead of trusty.
https://github.com/CTFd/CTFd/milestone/6