Start using MONGO_URL on cruncher

[joaopapereira]

Given a developer
When I set the environment variable MONGO_URL
And I start the application
Then the application will start connected to the set database

[tansaku]

Currently it relies on MONGOLAB_URI - using dokku:mongo we see that the default URL created when we link up is MONGO_URL so if we could have the cruncher either use this or fall back to it then that would simplify our deploy process

[tansaku]

this would involve a change in https://github.com/AgileVentures/MetPlus_resumeCruncher - searching over that repo we can see the places where the project refers to MONGOLAB_URI:

https://github.com/AgileVentures/MetPlus_resumeCruncher/search?q=MONGOLAB&unscoped_q=MONGOLAB

It looks to me like the key change would be in the Procfile, but maybe also in .s2i/bin/run and .openshift/action_hooks/start although I think those files might be specific to our old hosting provider openshift - @joaopapereira perhaps they should also be updated? deleted? ignored?

[joaopapereira]

I merged a PR that removes openshift support.