Update travis settings for release-branches
Update travis settings for release-branches

- drop the deprecated flag `--deployment` of bundle (so we have to specify the bundler caching path)

thu4nvd/thu4nvd.github.io,akshaysth/akshaysth.github.io,akshaysth/akshaysth.github.io,ankitrokdeonsns/ankitrokdeonsns.github.io,akshaysth/akshaysth.github.io,thu4nvd/thu4nvd.github.io,thu4nvd/thu4nvd.github.io,ankitrokdeonsns/ankitrokdeonsns.github.io,akshaysth/akshaysth.github.io