Revert "Try using Python 3.6.4 on travis since 3.6.5 brakes some tests in a"
Revert "Try using Python 3.6.4 on travis since 3.6.5 brakes some tests in a"

This reverts commit 78dbaedfe8505ce0729c04b23921b4c2547c46b4.

Plexxi/st2,nzlosh/st2,nzlosh/st2,nzlosh/st2,Plexxi/st2,StackStorm/st2,StackStorm/st2,Plexxi/st2,Plexxi/st2,StackStorm/st2,StackStorm/st2,nzlosh/st2