Use HTTPS for fetching resources

If you are on a locked-down network, like most large businesses, you can't just reach out over the git protocol to get repositories.

This patch stops npm from erroring with useful messages like this

    npm ERR! git clone git://github.com/karma-runner/karma-coverage Cloning into bare repository '/home/fidian/.npm/_git-remotes/git-github-com-karma-runner-karma-coverage-f5a5ab06'...
    npm ERR! git clone git://github.com/karma-runner/karma-coverage
    npm ERR! git clone git://github.com/karma-runner/karma-coverage fatal: unable to connect to github.com:
    npm ERR! git clone git://github.com/karma-runner/karma-coverage github.com[0: 192.30.252.129]: errno=Connection refused

and like this

	npm ERR! not a package /home/fidian/tmp/npm-17172/1382734998255-0.33902470069006085/tmp.tgz
	npm ERR! Error: ENOENT, open '/home/fidian/tmp/npm-17172/1382734998255-0.33902470069006085/package/package.json'