Stop ignoring the `Gemfile.lock`
Removes redundant example configuration files

We sold our souls to `mysql`
Removes redundant entries

* Removes heroku specific stuff
* Removes DB agnostic configuration
* Ensures `Gemfile.lock` is committed
Corrects travis configuration

* Cache bundled gems
* No longer supports rubies/DBs matrix as we deploy to 2.1.3/mysql
Merge pull request #2 from moneyadviceservice/travis-cleanup

Travis cleanup