Add sessions and login with slack.

Review Request #7237 — Created April 22, 2015 and submitted — Latest diff uploaded

Information

student-sonar
master
7d5b853...

Reviewers

This change adds access control to sonar, using Slack OAuth as a login
provider. This uses the 'passport' framework to handle the guts, and the
passport-slack provider to talk to Slack itself. Sessions are stored in
mongodb.

Logged in and out a whole bunch.