[travis-ci] clean up the travis.yml file slightly, make it pass travis-lint
[travis-ci] clean up the travis.yml file slightly, make it pass travis-lint

sndnvaps/lk,littlekernel/lk,srodrig1/lk,travisg/lk,sndnvaps/lk,littlekernel/lk,srodrig1/lk,sndnvaps/lk,travisg/lk,travisg/lk,ErikCorryGoogle/lk,minglun-tsai/lk,minglun-tsai/lk,sndnvaps/lk,ErikCorryGoogle/lk,skabet/lk,hollanderic/lkstuff,minglun-tsai/lk,srodrig1/lk,ErikCorryGoogle/lk,ErikCorryGoogle/lk,hollanderic/lkstuff,littlekernel/lk,skabet/lk,littlekernel/lk,srodrig1/lk,minglun-tsai/lk,skabet/lk,hollanderic/lkstuff,skabet/lk,travisg/lk,skabet/lk,sndnvaps/lk,srodrig1/lk,hollanderic/lkstuff