Fixed Bug in User.to_param
Updated Photofinder Task

- Pulling Twitter credentials from secrets.yml
- Logging authentication errors and exiting the task
Converted Helpers::Twitter Module into Services::TweetService Class
Fixed Bug in User.find_or_create_from_tweet!
Switched to Environment Variables for Secrets

 Necessary for Heroku deployment
Added Heroku Procfile
Added rails_12factor gem