CI: fix travis vs pytest 5
CI: fix travis vs pytest 5

spacetelescope/asv,spacetelescope/asv,qwhelan/asv,airspeed-velocity/asv,airspeed-velocity/asv,spacetelescope/asv,airspeed-velocity/asv,spacetelescope/asv,airspeed-velocity/asv,qwhelan/asv,qwhelan/asv,qwhelan/asv