Wercker integration for automated testing and deployments

#### What's this PR do?

*Make sure you have an account on wercker.  Add your wercker username to comments, so it can be added to the application*

Adds a wercker manifest that triggers builds and deployments in the Wercker environment.  Whenever new code is deployed to this repo, it will trigger a build on Wercker.  The build runs npm test.  It is currently setup up to automatically deploy to Nodejitsu trigger on changes to the master branch.

#### Where should the reviewer start?

*  Build - wercker.yml - The build steps are straight forward.  It runs npm install and then npm test.  The DB_URL environment variable is set from within the Wercker UI.
* Deploy - wercker.yml - I built a jitsu deployment step a while back and it seems to do the trick.  The username and password is set in the Wercker UI.

#### How should this be manually tested?

* Push a new branch upto this repo.  Then go to wercker app and confirm that the build has been started.

We should test the deployment on an actual merge to master.

#### What are the relevant tickets?


cc:  @jonuy