using redisStore for session storage

[AndrewSouthpaw]

Closes #135

Session storage should not be handled in-memory for production environments. It seems that using connect-redis is a common solution. I've implemented it here. However, I'm not sure it's working correctly; the front end is still broken enough that it's hard to tell.

Reference:

• connect-redis: https://github.com/tj/connect-redis
• Heroku Redis: https://devcenter.heroku.com/articles/rediscloud#using-redis-from-node-js

Take a look, see if it makes sense. I say we get the front-end up to a working condition, then merge in this PR to see if it still works.

[ruben1]

yes, i would try to display something first. I'll review after we have something working in the front-end