Use environmental variables, gems for dev, test

Using environmental variables.
===

Since this project is open source, it's safer to hide our personal
credentials for things such as database access. One way is set them as
environmental variables and have Rails read them. The benefit is we all
 don't have to have the same database name, login username, password.
Everybody could set it to what they so desire

New gems added for development, testing environments
===
`Thin` has a good reputation as a webserver, and I've used it for all my
Rails projects. `rspec-rails` is for TDD and BDD (along with `capybara`).
`meta_request` is required for the Rails Chrome browser plugin.

Mandatory file for `rbenv`
===
For all rbenv users, this will keep you safe. Don't panic if you are of the
rvm persuasion. It shouldn't interfere as rvm would completely ignore it