Add 1ms sleep to FileStreamReader to appease tornado
Add 1ms sleep to FileStreamReader to appease tornado

Tornado didn't like that `asyncio.sleep(0)` is hardcoded in CPython
3.5.1 to yield None.

rdhyee/waterbutler,Johnetordoff/waterbutler,felliott/waterbutler,CenterForOpenScience/waterbutler,TomBaxter/waterbutler,RCOSDP/waterbutler