fix(viewDirective): $injector.has() not in angular#1.0.8

`$injector.get()` doesn't throw unless the key is not useable (like an object), or unless there is a circular dependency, so there's no issue just using it this way, so that it doesn't break 1.0.8.

[1.0.8 does not provide $injector.has()](https://github.com/angular/angular.js/blob/56817e9faa5cb9ece762bb3d6332eb9fb98f9d59/src/auto/injector.js#L597)

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This bug breaks @mojjojo's app in 1.0.8, so a quick fix would be good for them.