Improve readme

Author: jorge-d

README.md

@@ -1,2 +1,9 @@
 # octobat
-Nodejs module that wraps the octobat API
+Nodejs module that wraps the octobat API. Highly inspirated by Stripe's node module.
+
+## Testing
+
+Ensure you have set your octobat api test key in your env:
+```sh
+echo 'export OCTOBAT_TEST_API_KEY=amazing' >> ~/.zhsrc
+```