README: change npm install to this fork

Author: LoicMahieu

README.md

@@ -17,7 +17,7 @@ The following helpers are designed to generate [mocha] tests against
 
 ## install
 
-1. `npm install loopback-testing --save-dev`
+1. `npm install github:igloo-be/loopback-testing --save-dev`
 2. Assuming you started with a clean template/project generated by `slc loopback`
   1. If you have mocha installed as a global npm module that's great! Simply update `<your_project>/package.json` with: