Loopback test

This is a simple html test framework to run a loopback test which can go via
turn. For now the test is used to analyse bandwidth estimation and get records
for bad scenarios.

How to run:
 ./run-server.sh (to start python serving the tests)
 Access http://localhost:8080/loopback_test.html to run the test

How to record:
 You can use record-test.sh to get a tcpdump of a test run.