login failure: KeyError: 'error'

login fails and it appears this is the culprit:
```python
    def login(self):
        # [...]
        if r.status_code != 200:
            print(r.json()["error"])
            quit(1)
```
It worked when I changed the status code to 201. Status code for successful login must have changed from previously 200. I recommend to change this to assume success on all 2xx status codes.