Create event updates mailing list

[daiyi]

Mailing list so people can sign up for updates and announcements. I was thinking mailchimp! because it allows multiple users until one organisation.

• [x] create mailing list
• [ ] add yall as users on the mailing list
• [ ] add signup form to website

[daiyi]

mailing list: http://eepurl.com/dAsNxT

[mkremins]

added a link to the standalone signup form page on the website, as a stopgap until we get the embedded version of the form in place