Re-add unit testing module

During the move from the project manager repo, the testing
module definition appears to have disappeared. It's back now.

projects.xml

@@ -34,6 +34,7 @@ Here are some examples:
     <module name="oculusVR" path="$OCULUSVR_SDK_PATH">Oculus VR Devices</module>
     <module name="webDeploy">Web Deployment</module>
     <module name="navigation">Recast Navigation</module>
+    <module name="testing">Unit testing</module>
     <moduleGroup description="Physics Library">
       <module name="" donotwrite="1" default="1">Torque Physics</module>
       <module name="physX">PhysX Physics Library</module>