Add A/B testing system

[hollomancer]

@rickr @RobKriner, I recall we were using Split for this before - https://github.com/splitrb/split

[rickr]

For this ticket you'll need to:

• [x] Evaluate A/B systems for node/react.
• [ ] Figure out how persistence/reporting works for that gem
• [ ] How persistence/reporting will interact with our rails backend.

[hollomancer]

Contacted Optimizely to get a sense of their nonprofit offerings.

[hollomancer]

Optimizely is out of our price range. Evaluated Google Optimize, but we need https://github.com/react-ga/react-ga/issues/135 fixed first, at least if we're going to use the react-ga gem.

[JennWeideman]

@hollomancer is this still something we can do?

[JennWeideman]

slack call tonight... whatever platform best fits our needs and budget? as along as @hollomancer @davidmolina give approval and I can track it! @kylemh @Cooperbuilt Thanks guys