Branch stateless-services contains invalid imports of angularfire2 modules. Running npm start yields the following errors:
ERROR in src/app/course-detail/course-detail.component.ts(2,9): error TS2305:
Module '".../node_modules/angularfire2/index"' has no exported member 'AngularFireDatabase'.
src/app/home/home.component.ts(2,9): error TS2305:
Module '".../node_modules/angularfire2/index"' has no exported member 'AngularFireDatabase'.
Pull request #7 - fixes this