feat(circleci): triggers grafana packer after successful build

Only triggers for main grafana repo (not forks) and when the
master branch is built.

circle.yml

@@ -27,3 +27,10 @@ test:
      # js tests
      - ./node_modules/grunt-cli/bin/grunt test
      - npm run coveralls
+
+deployment:
+  master:
+    branch: master
+    owner: grafana
+    commands: 
+      - ./trigger_grafana_packer.sh ${TRIGGER_GRAFANA_PACKER_CIRCLECI_TOKEN}

trigger_grafana_packer.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+_circle_token=$1
+
+trigger_build_url=https://circleci.com/api/v1/project/grafana/grafana-packer/tree/master?circle-token=${_circle_token}
+
+curl \
+--header "Accept: application/json" \
+--header "Content-Type: application/json" \
+--request POST ${trigger_build_url}