remove duplicate in readme
remove duplicate in readme

deskr/cayley,deskr/cayley,h4ck3rm1k3/cayley,deskr/cayley,pombredanne/cayley,barakmich/cayley,pombredanne/cayley,barakmich/cayley,cayleygraph/cayley,barakmich/cayley,h4ck3rm1k3/cayley,pombredanne/cayley,kortschak/cayley,kortschak/cayley,barakmich/cayley,cayleygraph/cayley,h4ck3rm1k3/cayley,pombredanne/cayley,deskr/cayley,h4ck3rm1k3/cayley,h4ck3rm1k3/cayley,kortschak/cayley,kortschak/cayley,kortschak/cayley,deskr/cayley,barakmich/cayley