Try getting the firefox beta on Circle.

heathkit · heathkit · commit 25c35807f488 · 2017-01-11T11:38:13.000-08:00
diff --git a/circle.yml b/circle.yml
@@ -19,6 +19,9 @@ dependencies:
     - cd testapp && npm update
     - npm start:
           background: true
+    - pip install mozdownload mozinstall
+    - mozdownload --version latest-beta --destination firefox.tar.bz2
+    - mozinstall firefox.tar.bz2
 
 test:
   override:
