Modify gitignore to allow bin/ and config/secrets.yml

Previous gitignore taken from Rails 3 project, Rails 4 needs bin/ to execute
Add bin/ to execute Rails 4

bin/ excluded from initial commit due to .gitignore copied from Rails 3 project
Re-added secrets.yml missing from previous commits
Merge pull request #109 from nealfennimore/fix/secrets.yml

Re-added secrets.yml missing from previous commits