clarify when issue tracker is to be used so as to not contradict issue tracker guidelines and maintenance policy

Hipchat service implementation

improve regrex for match(sidekiq) robustness

Fixed typo in Readme.md

Security: keep the Rails secret token out of version control.

Store the secret token in a .gitignored file called ".secret", which is
created by the initializer if it doesn't exist.

Fixed 22th -> 22nd

Fix cancel button link on edit files page