upgrade to ruby 2.1.4
Merge pull request #210 from bitzesty/ruby-2.1.4

upgrade to ruby 2.1.4
upgrade to rails 4

includes some amendments to specs to make them work
remove all frontend

API will be sending only JSON. Remove all frontend-related code & gems
Docker setup
remove gemset config
start sidekiq in fig.sh
use docker redis port/url if present
expose ports to the outside
use `macool/base-image-rbenv-docker`

to build docker image
use `foreman` to start webapp and worker
enhances to run with `tariff-docker`

- `database.yml` will need to reference other `ENV` variables when linking containers from `tariff-docker`

For more info see [bitzesty/tariff-docker](https://github.com/bitzesty/tariff-docker)
sidekiq compatibility with `tariff-docker`

change references to env variables for redis

For more info see [bitzesty/tariff-docker](https://github.com/bitzesty/tariff-docker)
we don't need `govuk_setenv` on this env
update crontab on startup.sh
use sentry
log development errors
perform `bundle install` upon startup
fig containers support for elasticsearch
better support of docker containers via ENV