Only track events in production

Our production environment has this environment variable set.
Track referrer in API requests
Track API calls under new property
Swap google analytics for mixpanel

Track url, ip, and referrer.
Merge pull request #17 from adorableio/ga_to_mixpanel

Swap google analytics for mixpanel
Fix inert integration test

The API hit is an async call, so we need to pass it a callback
lest errors get lost.
Use my fork of mixpanel

So we can track IP address
Track IP address

Our node module adds this configuration variable.
Change variable name

Mixpanel calls it a token, let's do the same
Assign a boolean to a predicate value
Merge pull request #18 from adorableio/tracking_fixes

Tracking fixes
Merge branch 'master' into manual_urls

* master:
  Assign a boolean to a predicate value
  Change variable name
  Track IP address
  Use my fork of mixpanel
  Fix inert integration test
  Swap google analytics for mixpanel
  Track API calls under new property
  Track referrer in API requests
  Only track events in production

Conflicts:
	lib/webserver.coffee
Move routing to separate module
Add back v1 functionality, scope old/new routes

Still need to bring back v1 image resizing.
Indicate private methods
Add back v1 resizing

Test all the current routes in our integration tests. With a better
understanding of supertest, refactor how we declare the tests.
Remove unused variables
Add route and code for specifying custom face parts
Move path to image folder to common definitions

Since it's used by both v1 and v2. Also, give it a better name.
More consistent comments