Add code coverage reports

Add [Coveralls][1] support via istanbul.
Update `Makefile` targets and `gitignore` list.

Update config exports

  Use an index to make imports less verbose:

      `require('../config')`

Misc

 - Bump dependencies
 - Refactor to use newer deps
 - Update deprecated API calls
 - Use newer Express style for json responses
 - Update bodyParser
 - Add application validation middleware

Tests

 - Refactor test folder layout (env, fixtures and acceptance)
 - Move test helper into `support` folder
 - Rename specs

[1]: coveralls.io
Return 201 on resource creation

Add admin/auth tests (disabled) and Job constraint validation tests.
Merge pull request #7 from cherta/gf-update_tests

Add code coverage reports