Create Angular boilerplate

Angular boilerplate generated using Yeoman. We haven't talked about
nginx setup yet, so for now, the results can be viewed by running
python -m SimpleHTTPServer 8000 from inside js/angular/app.

We are not planning to generate controllers, etc. using yeoman (e.g. yo
angular:controller) because this won't let us separate angular into
separate modules by function.
Merge pull request #4 from WorldBank-Transport/feature/start-angular

Create Angular boilerplate