Update to handle graphviz output empty graph
Update to handle graphviz output empty graph

aswathyjacob8/newtest,hackmdio/hackmd,jackycute/HackMD,jccrofty30/hackmd,ironhack/hackmd,PeterDaveHello/hackmd,Rwing/hackmd,ironhack/hackmd,Rwing/hackmd,Yukaii/hackmd,jackycute/HackMD,PeterDaveHello/hackmd,jccrofty30/hackmd,hackmdio/hackmd,PeterDaveHello/hackmd,jccrofty30/hackmd,Yukaii/hackmd,hackmdio/hackmd,aswathyjacob8/newtest,jackycute/HackMD,Yukaii/hackmd,Rwing/hackmd,aswathyjacob8/newtest,ironhack/hackmd