Contact Manager: Revisions

* Added more terminal tags to the introduction of creating a repo
* Revised RSpec installation instructions
* Revised Git installation instructions
Contact Manager - Revisions

* RSpec install
* Unicorn
* Heroku
Contact Manager

* changed remaining `bundle exec rake` to state "run your tests"
* added the migration to make it clearer what is going on
Contact Manager: Replaced  with 'run your tests'