http-server dependency was changed to git master version by commit
bdb181cb08 because it required
30f4d1e008,
which is now included in http-server v0.8.0.

This fixes the warning issued at `npm install` time.

swagger-client@2.1.0-M2.alpha2 need to get published for this

* Uses npm to download latest swagger-js (for now. When swagger-js is
   released we will replace git address with actual swagger-ui)

* Uses `postinstall` to generate `browser` folder of swagger-ui. This
 can go when swagger-ui is published.

* For the e2e tests to run, we had to enable CORS in http-server.  The
  release of http-server that supports CORS hasn't come out yet so we
  have to use http-server@master until then.  Here is the commit I speak
  of: 30f4d1e008

Avoid too many repeatations