Force karma to use the latest 0.9.x working version of socket.io

When running karma tests with `ddescribe` or `iit`, as well as in some other
cases, the browser gets disconnected for some reason.

The full information on this fix can be found in:
http://jamiolkowski.it/251/karma-runner-warn-chrome-35-0-1916-mac-os-x-10-8-5-disconnected-1-times/