* fix heartbeatTimeout of NONE resulting in ValueError and polling returning empty string taskToken when it shouldn't be returned
* fix expected taskToken in impacted tests
Co-authored-by: Clint Parham <cparham@aligntech.com>
This is a second barrier because I'm a little nervous about this and I
don't want moto/swf to make any activity progress while in the real
world service, it's strictly impossible once the execution is closed.
Python doesn't seem to have any nice way of freezing an object so here
we go with a manual boundary...
When launched manually, tests should be launched with the environment
variable TZ=GMT. Maybe this could be useful to add that explicitly
somewhere in the README or in the Makefile.
