Add port arg to unicorn command.
Fix local dalli cache error by using ActiveSupport MemoryStore in development.

Dalli will continue to be used if app is in production environment.
Bundle update all outdated gems and use Ruby 2.1.1.

* Remove json and eco gems as they are unused.
* Add production group with rails_12factor and newrelic_rpm for heroku
compatibility.
* Move memcachier and dalli to production group.
* Use standard sinatra-contrib.
* Replace debugger with rack-mini-profiler