Running molotov directly causes X-Weave-Timestamp error

[rpappalax]

$ molotov --max-runs 5 -cxv loadtest.py
**** Molotov v2.0. Happy breaking! ****
Preparing 1 worker...
OK
KeyError('X-Weave-Timestamp')WORKERS: 1
  File "/Users/rpappalax/git/synctests/syncstorage-loadtest/venv/lib/python3.7/site-packages/molotov/worker.py", line 205, in step
    await scenario["func"](session, *scenario["args"], **scenario["kw"])
  File "loadtest.py", line 73, in test
    _, config = await storage.get("/info/configuration")
  File "./storage/__init__.py", line 253, in get
    statuses=statuses)
  File "./storage/__init__.py", line 220, in _retry
    server_time = int(float(resp.headers["X-Weave-Timestamp"]))
SUCCESSES: 0 | FAILURES: 1
*** Bye ***