Test dfs_edges.  Addresses #418
Test dfs_edges.  Addresses #418

jakevdp/networkx,wasade/networkx,sharifulgeo/networkx,jakevdp/networkx,Sixshaman/networkx,ghdk/networkx,ltiao/networkx,kai5263499/networkx,bzero/networkx,dhimmel/networkx,cmtm/networkx,sharifulgeo/networkx,kai5263499/networkx,ionanrozenfeld/networkx,harlowja/networkx,michaelpacer/networkx,OrkoHunter/networkx,farhaanbukhsh/networkx,RMKD/networkx,goulu/networkx,tmilicic/networkx,SanketDG/networkx,chrisnatali/networkx,harlowja/networkx,JamesClough/networkx,debsankha/networkx,kernc/networkx,kai5263499/networkx,RMKD/networkx,RMKD/networkx,sharifulgeo/networkx,farhaanbukhsh/networkx,blublud/networkx,jtorrents/networkx,ionanrozenfeld/networkx,aureooms/networkx,ionanrozenfeld/networkx,farhaanbukhsh/networkx,kernc/networkx,jni/networkx,aureooms/networkx,beni55/networkx,NvanAdrichem/networkx,jni/networkx,dmoliveira/networkx,dhimmel/networkx,harlowja/networkx,aureooms/networkx,nathania/networkx,debsankha/networkx,jfinkels/networkx,yashu-seth/networkx,bzero/networkx,ghdk/networkx,jakevdp/networkx,debsankha/networkx,kernc/networkx,chrisnatali/networkx,nathania/networkx,dhimmel/networkx,blublud/networkx,jtorrents/networkx,dmoliveira/networkx,nathania/networkx,blublud/networkx,dmoliveira/networkx,chrisnatali/networkx,ghdk/networkx,jcurbelo/networkx,bzero/networkx,andnovar/networkx,jni/networkx