Discovery: Foundation for email encoding and basic templating

[gsidebo]

http://foundation.zurb.com/emails.html

Foundation for Emails is a framework for creating responsive HTML emails. A tool like this would fit into our workflow like so:

• A user composes an email in the MicroMasters app and hits Submit/Send
• Foundation is used to take that user input and create a properly-encoded, responsive email body (perhaps with our choice of template)
• The email body is sent to our chosen email service (likely Mailgun) to send to the list of recipients

Our initial use case (instructors sending text-only emails to a selected list of learners) will not require Foundation's HTML-encoding or responsiveness features, but we'll want HTML-encoding in the future and possibly responsiveness.

Some criteria to consider during evaluation:

• How difficult would it be to integrate Foundation into the MicroMasters?
• How easy is it to create and use a custom template with a simple header and footer for an outgoing email?
• How easy is it to send a simple email with some number of responsive buttons/images, and how does it look in a mobile screen? Chrome dev tools can be used to test this

(This issue was originally listed as part of #694)