update travis to run tests not in parallel
update travis to run tests not in parallel

bradley219/migrate,YuukiHogo/migrate,schickling/migrate,yannh/migrate,turbine/migrate,heetch/migrate,jadeydi/migrate,lepoetemaudit/migrate,jhellan/migrate,PlanitarInc/migrate,Synesis-LLC/migrate,gunosy/migrate,buddhamagnet/migrate,divoxx/migrate,hlandauf/migrate