Added Gitter.im

Added Gitter to chat services (disclaimer: I am a co-founder of Gitter). I also fixed the URL of one of our competitors (Pie) which was incorrect and added MongoHQ to the Database-aas list.
Fixed pie URL
Merge branch 'master' of https://github.com/cjbarber/ToolsOfTheTrade into patch-1

Conflicts:
	README.md
Removed extra newline
Merge pull request #173 from suprememoocow/patch-1

Added Gitter.im