Fix katz centrality doctest formatting
Fix katz centrality doctest formatting

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