Fix CircleCI problems during go get promu

sdurrheimer · sdurrheimer · commit 28d33e0a5d0c · 2016-05-05T13:12:19.000+02:00
diff --git a/circle.yml b/circle.yml
@@ -13,7 +13,7 @@ machine:
 
 dependencies:
   pre:
-    - go get -u github.com/prometheus/promu
+    - make promu
     - docker info
   override:
     - promu crossbuild
