[NTG-context] install-modules script and git URLs

Hi Hraban and Taco, the install-modules script doesn’t allow .tar.gz as compression format to install modules. .tar.gz seems to be the compression format offered for modules that are uploaded using a git URL. Hraban explained in August that thee server could be configured to get .zip compression for modules in git checkout. Sorry, I know that you are both very busy, but could it be this issue fixed? Using git to upload module versions is way more easy than uploading .zip files. Many thanks for your help to both, Pablo