Plugins Add : repo name must be lowercase

[Clem-]

Describe the bug
When running plugins add command, the last part of the repo url is used for the foldername.
This foldername is then used as the reposityory name that must be lowercase.
Since the repo URL is not lowercase, an error occurs.

To Reproduce
Steps to reproduce the behavior:

1. docker compose -f docker-compose.onpremise.mongo.yml exec plugins add https://github.com/linagora/Twake-Plugins-SimplePoll.git simplepoll secret

Expected behavior
Plugins should be built successfully

Screenshots

Waiting for SIMPLEPOLL.GIT build
/usr/src/app/helpers/add.js:63
if (err) throw err;
^

Error: Command failed: build SimplePoll.git && up SimplePoll.git
/usr/src/app/helpers/build.js:17
if (err) throw err;
^

Error: Command failed: cd /usr/src/app/plugins/SimplePoll.git && docker build -t SimplePoll.git . && cd ../..
invalid argument "SimplePoll.git" for "-t, --tag" flag: invalid reference format: repository name must be lowercase