Push branch with dulwich

usage: push.py [-h] [--config CONFIG] [--debug] REPO BRANCH

Push a Git branch using `dulwich`.

positional arguments:
  REPO             path to local repository
  BRANCH           branch to push

optional arguments:
  -h, --help       show this help message and exit
  --config CONFIG  configuration file (default: .credentials)
  --debug          enable debugging output

The configuration file should contain the following sections, keys and values:

[Git repository]
url = https://example.com/your-repo-url.git

[Git credentials]
username = your-username
api_token = an-api-token-or-password