Install firebase on travis

Author: andrewda

.travis.yml

@@ -5,6 +5,9 @@ rvm:
 before_install:
   - nvm install 7
   - npm install
+  
+install:
+  - npm install -g firebase-tools
 
 script:
   - npm run build
@@ -16,4 +19,4 @@ after_success:
 notifications:
   email:
     on_failure: change
-    on_success: change
+    on_success: change