Upgrade mysql

[icarito]

This is a first step of a two step-process to upgrade to MySql 5.7 in production.
Hopefully will help with https://github.com/jywarren/web/issues/94

Make sure these boxes are checked before your pull request is ready to be reviewed and merged. Thanks!

• all tests pass -- rake test:all
• code is in uniquely-named feature branch, and has been rebased on top of latest master (especially if you've been asked to make additional changes)
• pull request is descriptively named with #number reference back to original issue

[PublicLabBot]

	1 Warning
⚠️	It looks like you merged from master in this pull request. Please rebase to get rid of the merge commits – you may want to rewind the master branch and rebase instead of merging in from master, which can cause problems when accepting new code!

	4 Messages
📖	@icarito Thank you for your pull request! I’m here to help with some tips and recommendations. Please take a look at the list provided and help us review and accept your contribution!
📖	This pull request doesn’t link to a issue number. Please refer to the issue it fixes (if any) in the format: Fixes #123.
📖	You have added multiple commits. It’s helpful to squash them if the individual changes are small.
📖	It looks like you haven’t marked all the checkboxes. Help us review and accept your suggested changes by going through the steps one by one. If it is still a ‘Work in progresss’, please include ‘[WIP]’ in the title.

Generated by 🚫 Danger

[icarito]

superseded by #1428