Fix bug where debug "return" prevented whole TestAtomicUpdate run
use atomic create in EtcdHelper.AtomicUpdate
Make fake_etcd_client threadsafe
Add test for EtcdHelper.AtomicUpdate concurrent create
Merge pull request #694 from nyaxt/atomicetcd

Use atomic create in EtcdHelper.AtomicUpdate
Revert "Use atomic create in EtcdHelper.AtomicUpdate"
Merge pull request #793 from GoogleCloudPlatform/revert-694-atomicetcd

Revert "Use atomic create in EtcdHelper.AtomicUpdate"
Add dns-952-identifier validation to service ids.