Start etcd with V2 API enabled for V2 etcd acceptance tests
Otherwise, the etcd (not etcd3) behave tests fail to connect:
```
Jan 02 09:56:18 HOOK-ERROR in before_all: AssertionError: etcd instance is not available for queries after 5 seconds
```
@@ -441,7 +441,7 @@ class AbstractEtcdController(AbstractDcsController):
self._client_cls = client_cls
def _start(self):
- return subprocess.Popen(["etcd", "--data-dir", self._work_directory],
+ return subprocess.Popen(["etcd", "--enable-v2=true", "--data-dir", self._work_directory],
stdout=self._log, stderr=subprocess.STDOUT)
def _is_running(self):
