Added removeToast observable.

[CaselIT]

At last I've found some time to implement this feature.
This implements #42

To avoid exposing the public _removeToastSubject in the ToasterService I've added the flag stripInternal in the tsconfig. If you prefer another solution let me know and I'll change the commit.

[coveralls]

Coverage remained the same at 100.0% when pulling 098dbb6876ff791be0bea13dc0631ad8deba0f8d on CaselIT:removeToast into d9bcafa on Stabzs:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 9d148f5 on CaselIT:removeToast into d9bcafa on Stabzs:master.

[CaselIT]

I replaced the previous commit since I had inadvertently formatted the whole ToastService file, adding unnecessary formatting changes.

[Stabzs]

Thanks for getting to this!

I think that the stripInternal flag is probably a pretty appropriate solution for this particular use case and while this is the only place it would currently be used, it seems worthwhile to use it.

[CaselIT]

Thanks for merging.
👍

[Stabzs]

You're welcome! This will go in the next feature build.

[Stabzs]

@CaselIT this is now published as 0.5.2-rc.7.

[CaselIT]

Great, thanks @Stabzs