Update http-proxy to the last version
Update http-proxy to the last version

The current version has its dependencies unpinned which at the moment causes a strange error as described in issue #95.

closes #95
vstars/grunt-connect-proxy,watsoncj/grunt-connect-proxy,matthieubulte/grunt-connect-proxy,drewzboto/grunt-connect-proxy,Backline/grunt-connect-proxy