Upgrade pystachio to 0.8.3
Upgrade pystachio to 0.8.3

Testing Done:
src/test/sh/org/apache/aurora/e2e/test_end_to_end.sh

Reviewed at https://reviews.apache.org/r/52790/

thinker0/aurora,apache/aurora,crashlytics/aurora,thinker0/aurora,rdelval/aurora,apache/aurora,thinker0/aurora,rdelval/aurora,apache/aurora,medallia/aurora,rdelval/aurora,rdelval/aurora,apache/aurora,rdelval/aurora,thinker0/aurora,crashlytics/aurora,medallia/aurora,crashlytics/aurora,crashlytics/aurora,medallia/aurora,medallia/aurora,medallia/aurora,crashlytics/aurora,crashlytics/aurora,apache/aurora,apache/aurora,thinker0/aurora,thinker0/aurora,medallia/aurora,rdelval/aurora