adding libnotify, removing nvm monkeypatch

Author: rosshinkley

circle.yml

@@ -1,8 +1,8 @@
-machine:
-  node:
-    version: 4.0.0
+dependencies:
+  pre:
+    - sudo apt-get update; sudo apt-get install libnotify-bin
 test:
   override:
     - nvm use 4 && npm test
     - nvm use 5 && npm test
-    - nvm install 6 && nvm use 6 && npm test
+    - nvm use 6 && npm test