May be this:
If the mashup web page is hosted by the IIS server then you are likely not authorizing to Qlik and consequently not able to get a web socket handshake.
The simple thing to do at this point to validate the mashup works is to have the Sense server host it. To do this, zip up the html file and the test.js file and then go to the QMC and import as an extension. From there you will be able to load it in a web browser once you auth to Qlik (default is windows auth).