add Clever-Dev-CI hipchat notifications via .drone.yml
use mongo2.6 explicitly
Set rs.initiate(), use mongo service which starts with --replSet TailTest

We need the mongo server to be a primary, which means we need to
run rs.initiate(), which means we need to have a client that is
the same version as our server, hence the apt-get installing.

We also need to have the server start up with a replSet.
Merge pull request #1 from Clever/clean-up-the-unix

clean up unix and drone