feat(@schematics/angular): remove deprecated http package

[cexbrayat]

Now that @angular/http is officially deprecated, we can probably remove it from the default package.json.

[cyrilletuzi]

@angular/platform-server, which soon will be included by an universal schematic, still requires @angular/http to respect the depreciation cycle (see angular/angular#19788).

So it may be removed by default to avoid confusion, but then #254 should install it.

[cexbrayat]

Closing as @Brocco made another PR and merged it in (#273)

[Brocco]

My bad... I hadn't noticed this PR 🤭... also my PR was reverted as HTTP is still being used internally... it will get removed when those other places are cleaned up.