updated circleci build-container version

.circleci/config.yml

@@ -232,7 +232,7 @@ jobs:
 
   build-enterprise:
     docker:
-     - image: grafana/build-container:v0.1
+     - image: grafana/build-container:1.2.0
     working_directory: /go/src/github.com/grafana/grafana
     steps:
       - checkout