Ensure that intermittent-tracker is always upgraded when the revision…

… changes.
servo · bors-servo · Nov 3, 2017 · Oct 25, 2017 · Oct 25, 2017 · Oct 25, 2017
commit a2934d015b300086b1f6194f5b69d785ebaf4df0
diff --git a/intermittent-tracker/init.sls b/intermittent-tracker/init.sls
@@ -21,6 +21,7 @@ intermittent-tracker:
     - pkgs:
       - git+https://github.com/servo/intermittent-tracker@{{ tracker.rev }}
     - bin_env: /home/servo/intermittent-tracker/_venv
+    - upgrade: True
     - require:
       - virtualenv: intermittent-tracker
   {% if grains.get('virtual_subtype', '') != 'Docker' %}