Switched database from Postgres to SQLite

(In order for contributors to be able to easily set up the application on their machines.)
Merge pull request #17 from karlhigley/master

Switched database from Postgres to SQLite.
Updated the README with instructions to get the application running on local machines
Merge branch 'master' of github.com:districtem/rgmanager

Conflicts:
	Gemfile
	Gemfile.lock