fleetlock: Use patched server from Github PR

The _fleetlock_ server drains all pods from a node before allocating the
reboot lock to that node.  Unfortunately, it doesn't actually wait for
those pods to be completely evicted.  If some pods take too long to shut
down, they may get stuck in `Terminating` state once the machine starts
rebooting.  This makes it so those pods cannot be replaced on another
node with the original one is offline, which pretty much defeats the
purpose of using Fleetlock in the first place.

It seems upstream has abandoned this project, as there is an open [Pull
Request][0] to fix this issue that has so far been ignored.
Fortunately, building a new container image containing the patch is easy
enough, so we can run our own patched build.

[0]: https://github.com/poseidon/fleetlock/pull/271

fleetlock/kustomization.yaml

@@ -19,3 +19,8 @@ patches:
       name: fleetlock
     spec:
       clusterIP: 10.96.1.15
+
+images:
+- name: quay.io/poseidon/fleetlock
+  newName: git.pyrocufflink.net/containerimages/fleetlock
+  newTag: vadimberezniker-wait_evictions