Attempt to fix CircleCI tests

circle.yml

@@ -1,6 +1,8 @@
 machine:
   node:
     version: v6.1.0
+  environment:
+    CIRCLECI: true
 
 compile:
   override:
@@ -8,5 +10,7 @@ compile:
     - npm run build
 
 test:
+  pre:
+    - echo "\$CIRCLECI is $CIRCLECI"
   post:
     - npm run lint