send email

Changelog
=========
* Create a  ```local_env.yml``` file to save all variables
* Add ```mini_magick``` because is a necessary dependence.
* Add ```Sideqkiq``` gem to send email in background.
* Create a ```customer_mailer.rb``` and  ```customer_mailer.rb``` The email of Happy birthday.
* Add Configuration to send an email by **Gmail smtp**.
* Add new routes to email. 
* Add new modal view to send email in Landing Page