Merge branch 'release/0.2.0'
mongodb-2.2 cartridge no longer available

mongodb-2.2 cartridge is no longer available in OpenShift, but mongodb-2.4.
Merge pull request #26 from rtnpro/patch-1

mongodb-2.2 cartridge no longer available
Merge branch 'master' into develop
Use python 2.7 instead of 2.6