deflake tests.
Merge pull request #887 from brendandburns/proxy

Deflake proxy unit tests.
Add a tear down option to the e2e, that just tears down the cluster
Useful for cleaning state after failed runs.
Merge pull request #892 from brendandburns/teardown

Add a teardown option to the e2e, that just tears down the cluster, also make gce teardown synchronous.