Re-enable `tip` in .travis.yml
Re-enable `tip` in .travis.yml

We want to know if breaking changes are coming our way
pombredanne/cayley,deskr/cayley,kortschak/cayley,pombredanne/cayley,barakmich/cayley,h4ck3rm1k3/cayley,deskr/cayley,kortschak/cayley,pombredanne/cayley,barakmich/cayley,deskr/cayley,h4ck3rm1k3/cayley,h4ck3rm1k3/cayley,h4ck3rm1k3/cayley,kortschak/cayley,h4ck3rm1k3/cayley,pombredanne/cayley,cayleygraph/cayley,kortschak/cayley,cayleygraph/cayley,barakmich/cayley,deskr/cayley,kortschak/cayley,deskr/cayley,barakmich/cayley,barakmich/cayley