Rework .travis.yml to use wheels.
Rework .travis.yml to use wheels.

ltiao/networkx,ionanrozenfeld/networkx,harlowja/networkx,kernc/networkx,blublud/networkx,JamesClough/networkx,jakevdp/networkx,dmoliveira/networkx,jakevdp/networkx,SanketDG/networkx,harlowja/networkx,nathania/networkx,dmoliveira/networkx,chrisnatali/networkx,ghdk/networkx,sharifulgeo/networkx,jni/networkx,michaelpacer/networkx,aureooms/networkx,sharifulgeo/networkx,dhimmel/networkx,debsankha/networkx,farhaanbukhsh/networkx,yashu-seth/networkx,harlowja/networkx,jakevdp/networkx,ghdk/networkx,chrisnatali/networkx,blublud/networkx,OrkoHunter/networkx,nathania/networkx,jfinkels/networkx,chrisnatali/networkx,farhaanbukhsh/networkx,jcurbelo/networkx,debsankha/networkx,sharifulgeo/networkx,andnovar/networkx,kernc/networkx,blublud/networkx,aureooms/networkx,farhaanbukhsh/networkx,RMKD/networkx,bzero/networkx,dmoliveira/networkx,RMKD/networkx,nathania/networkx,ionanrozenfeld/networkx,jni/networkx,ionanrozenfeld/networkx,RMKD/networkx,bzero/networkx,aureooms/networkx,goulu/networkx,dhimmel/networkx,cmtm/networkx,beni55/networkx,dhimmel/networkx,kernc/networkx,wasade/networkx,NvanAdrichem/networkx,Sixshaman/networkx,tmilicic/networkx,jni/networkx,bzero/networkx,debsankha/networkx,ghdk/networkx