git_resource extension makes bad assumptions about repo url

[CafeLungo]

The git_resource plugin assumes the protocol is ssh, and it also assumes the ssh port is 22. This does not work if your git server is using a different port. It is also incompatible with the protocol portion of the URL. For example git+ssh://myurl.com:2222/my_repo.git is not identified as a URL, but instead as a directory:

Use case: git+ssh://myurl.com:2222/my_repo.git:
Actual result:
It assumes this is a directory:

Error in docker_build: error reading dockerfile: open /Users/user/Documents/workspace/my_project/git+ssh:/git@myurl.com:2222/my_repo.git/Dockerfile:

Expected result:
Cloning into /Users/user/Library/Application Support/tilt-dev/.git-sources/my_repo from git+ssh://myurl.com:2222

Use case: myurl.com:2222/my_repo.git:
Actual result:
It makes assumptions about the ssh server:

cloning into '/Users/user/Library/Application Support/tilt-dev/.git-sources/my_repo'...
ssh: connect to host myurl.com port 22: Operation timed out

Expected result:
Cloning into /Users/user/Library/Application Support/tilt-dev/.git-sources/my_repo from git+ssh://myurl.com:2222/my_repo