Update .travis.yml
Update .travis.yml

Temporary hack to fix .travis.yml.  RDKit on omnia currently requires boost 1.59.0 instead of 1.60.0
ktaneishi/deepchem,miaecle/deepchem,miaecle/deepchem,Agent007/deepchem,rbharath/deepchem,miaecle/deepchem,lilleswing/deepchem,deepchem/deepchem,Agent007/deepchem,Agent007/deepchem,joegomes/deepchem,ktaneishi/deepchem,peastman/deepchem,joegomes/deepchem,rbharath/deepchem,peastman/deepchem,lilleswing/deepchem,lilleswing/deepchem,deepchem/deepchem,ktaneishi/deepchem