Copy swagger files using grunt-contrib-copy.

This is more maintainable than our home-grown copy and works on earlier
versions of node.
Don't force in Travis. We want to see warnings and failures.
For some reason, I though `grunt install` was a thing...
Accommodate bad practices of swagger-ui library

The swagger-ui project broke backward compatibility in a number of
ways without incrementing the version number at all, it looks like.
This change brings us up to date to use the new swagger-ui API, as
well as the new version of the swagger specification itself (1.2).
Merge pull request #81 from girder/fix-init-copy

Copy swagger files using grunt-contrib-copy.