timeout broken?

[meetar]

http://tangrams.github.io/differ/?1=https://github.com/tangrams/differ-tests/blob/master/unit-tests/unittests01.json&2=&lib1=https://github.com/tangrams/tangram/blob/master/dist/tangram.debug.js?raw&lib2=https://github.com/tangrams/tangram/blob/master@%7B1month%7D/dist/tangram.debug.js?raw&go

hangs on the "script" test with:

Refused to execute script from 'https://raw.githubusercontent.com/tangrams/differ-tests/master/unit-tests/sources/external_script.js' because its MIME type ('text/plain') is not executable, and strict MIME type checking is enabled.

…and never continues.

It should give up on the test after the timeout limit and continue the other tests.