change circleci node image to 6.12.3 to ensure node 6 compat.

LinusBorg · LinusBorg · commit e1ba1ea34fdd · 2018-01-13T21:34:14.000+01:00
diff --git a/.circleci/config.yml b/.circleci/config.yml
@@ -1,7 +1,7 @@
 version: 2
 vm_settings: &vm_settings
   docker:
-    - image: circleci/node:8.9.4-browsers
+    - image: circleci/node:6.12.3-browsers
 
 jobs:
   install_template_deps:
