feat(grunt-tasks): Add automation for common tasks with Grunt.

Closes #12, #8 and #11 
Run:
* `grunt` to run the servers by default.
* `grunt server` to run the servers.
* `grunt server:web` to run only the web server (includes background tasks).
* `grunt server:docs` to run only the documentation server.

* `grunt db` to rebase and seed.
* `grunt db:rebase` to rebase.
* `grunt db:seed` to seed.

* `grunt docs` to build the documentation.

* `grunt test` to run unit tests by default.
* `grunt test:unit` to run unit tests.
* `grunt test:e2e` to run integration tests.
* `grunt test:ci` to run all tests on source change.