Implement client.license.upload() methods

Implement:

- `client.license.upload_with_ssh_key()`
- `client.license.upload_with_ssh_pass()`

See: 

- [library code](https://github.com/hpe-container-platform-community/hpecp-python-library/blob/master/hpecp/license.py#L27-L43)
- [cli code](https://github.com/hpe-container-platform-community/hpecp-python-library/blob/master/bin/cli.py#L354-L378)
