rip out google auth

[codefromthecrypt]

During #119, we noticed there's still a dependency on google's oauth library which is getting subverting our dependency management. What's happening is it has not only a strict dep on census, but census itself starts dragging in other grpc libraries.

Exception in thread "AsyncReporter{StorageComponent}" java.lang.NoClassDefFoundError: io/grpc/Context
	at io.opencensus.trace.CurrentSpanUtils.getCurrentSpan(CurrentSpanUtils.java:37)
	at io.opencensus.trace.Tracer.spanBuilder(Tracer.java:308)
	at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:848)
	at com.google.auth.oauth2.ServiceAccountCredentials.refreshAccessToken(ServiceAccountCredentials.java:429)

Notably the maintainers of google's http library marked my bug as a "question" even after someone else acked this is a problem googleapis/google-http-java-client#621

[anuraaga]

@saturnism Can you follow up on the upstream bug? It's probably a net loss for everyone if users roll their own auth because the auth library got too bloated.

[codefromthecrypt]

agreed. also it is both an issue of bloat and more importantly pinning to unstable libraries. That said, because this is a leaf module for us, it is more about bloat because we have no plans to use the libraries they are pinning to internally.

[elefeint]

I am following up internally (Ray is finally on vacation!)

[codefromthecrypt]

sadly this is still an issue