<NME> test-requirements.txt
<BEF> argon2-cffi>=16.1.0
factory-boy<3.3.0
httmock==1.3.0
testfixtures==6.10.3
tox

<MSG> Added asyntest requirement.

<DFF> @@ -3,3 +3,4 @@ factory-boy>=2.4
 httmock==1.3.0
 testfixtures==6.10.3
 tox
+asynctest

Added asyntest requirement.