Use same tsc settings as in loopback-next

[bajtos]

Once https://github.com/strongloop/loopback-next/issues/174 is done and published, we should start following LoopBack.next conventions in this project too.

~~As a short-term workaround, we may want to copy (duplicate) tslint config files and the relevant parts of tsconfig.~~

cc @superkhau @ritch

[dhmlau]

@bajtos , is it still valid?

[virkt25]

I don't think so since this project now uses @loopback/build

[bajtos]

AFAICT, we are using tslint configuration from @loopback/build (see tslint.json), but we are not using the shared typescript config yet (see tsconfig.json).

I have edited the issue to reflect the fact that it's only tsconfig to change.