Create 2.x branch and change master to use Loopback 3.0

[davidcheung]

So ci tests against loopback 3.0

https://github.com/strongloop-internal/scrum-loopback/issues/1057

[davidcheung]

• should finish this first Generate AngularSdk not working using this module #236 before branching off to 3.x

[davidcheung]

blocked by strongloop/strong-remoting#360 where model.createMany uses batch create