[WIP] Add switcher

This tool can be used as CE/EE switcher

switch ce
switch ee

There is a little convention: your database names should be prefixed with _ce and _ee and the same with repositories folder (you should have two folders repositories and repositories_ee or repositories_ce).

In other words, this switcher just replaces prefixes in your database.yml and renames folders repositories to repositories_ce and repositories_ee to repositories. That's it