travis.yml: deploy docs on master and tag builds
travis.yml: deploy docs on master and tag builds

Signed-off-by: Niklas Koep <342d5290239d9c5264c8f98185afedb99596601a@gmail.com>

nkoep/pymanopt,pymanopt/pymanopt,nkoep/pymanopt,pymanopt/pymanopt,nkoep/pymanopt