Included the figaro gem.
Added a new feature, sending welcome mail to new come users.
Renamed UserMailer to AppMailer.
Included the letter_opener gem.
Set up the mail configuration for production environment.
Added tests to mail sending.
Set up mail configurations.
Skip required user for the ui controller.
Added forgot_password and email_password_token feature.
Added the reset password feature.
Renamed the table password resets to reset password tokens.
Refactored by solution video, Created the forgot passwords controller and moved codes from users controller into there.
Changed namings.
Refactored by solution video, created the password resets controller and moved codes from users controller into there.
Changed some test syntaxes.
Set up host for production to heroku.
Merge pull request #8 from HenrykChiu/week_4_code_review_2

Week 4 code review 2