Broken link in README.md

[vsiegel]

The link to bvlc-googlenet is broken, it is missing "/models":

It links to
https://github.com/yosinski/deep-visualization-toolbox/blob/master/bvlc-googlenet but should link to
https://github.com/yosinski/deep-visualization-toolbox/blob/master/models/bvlc-googlenet
instead,
analogous to the links to other models.