Add support for bearer token authorization

[ametzger]

This adds support for Authorization: Bearer <some_token>-style authorization to Jira. This is relevant in cases where someone has a Jira Server on which they have disabled basic authentication. For these users, using a Personal Access Token in combination with this change will allow authorization where basic_auth will not.

This is currently achievable by setting the options parameter in the constructor (see Jellyfish-AI/jf_agent#161) but that does not play nicely with the default headers.

Please let me know if this isn't clear or doesn't abide by proper contribution guidelines.

In action:

In [1]: from jira import JIRA

In [2]: personal_access_token = '<redacted>'

In [3]: j = JIRA('http://localhost:8080', basic_auth=('<redacted>', personal_access_token))
---------------------------------------------------------------------------
JIRAError                                 Traceback (most recent call last)
<ipython-input-3-c1f3b39bc65e> in <module>
----> 1 j = JIRA('http://localhost:8080', basic_auth=('<redacted>', personal_access_token))

~/proj/vendor/jira/jira/client.py in __init__(self, server, options, basic_auth, token_auth, oauth, jwt, kerberos, kerberos_options, validate, get_server_info, async_, async_workers, logging, max_retries, proxies, timeout, auth)
    517         if get_server_info:
    518             # We need version in order to know what API calls are available or not
--> 519             si = self.server_info()
    520             try:
    521                 self._version = tuple(si["versionNumbers"])

~/proj/vendor/jira/jira/client.py in server_info(self)
   2834         """
   2835         retry = 0
-> 2836         j = self._get_json("serverInfo")
   2837         while not j and retry < 3:
   2838             self.log.warning(

~/proj/vendor/jira/jira/client.py in _get_json(self, path, params, base)
   3488         """
   3489         url = self._get_url(path, base)
-> 3490         r = self._session.get(url, params=params)
   3491         try:
   3492             r_json = json_loads(r)

~/proj/vendor/jira/jira/resilientsession.py in get(self, url, **kwargs)
    193
    194     def get(self, url: Union[str, bytes], **kwargs) -> Response:  # type: ignore
--> 195         return self.__verb("GET", str(url), **kwargs)
    196
    197     def post(self, url: Union[str, bytes], data=None, json=None, **kwargs) -> Response:  # type: ignore

~/proj/vendor/jira/jira/resilientsession.py in __verb(self, verb, url, retry_data, **kwargs)
    187         if exception is not None:
    188             raise exception
--> 189         raise_on_error(response, verb=verb, **kwargs)
    190         # after raise_on_error, only Response objects are allowed through
    191         response = cast(Response, response)  # tell mypy only Response-like are here

~/proj/vendor/jira/jira/resilientsession.py in raise_on_error(r, verb, **kwargs)
     68             request=request,
     69             response=r,
---> 70             **kwargs,
     71         )
     72     # for debugging weird errors on CI

JIRAError: JiraError HTTP 403 url: http://localhost:8080/rest/api/2/serverInfo
        text: Basic Authentication has been disabled on this instance.

        response headers = {'X-AREQUESTID': '1275x843x1', 'Referrer-Policy': 'strict-origin-when-cross-origin', 'X-XSS-Protection': '1; mode=block', 'X-Content-Type-Options': 'nosniff', 'X-Frame-Options': 'SAMEORIGIN', 'Content-Security-Policy': 'sandbox', 'Strict-Transport-Security': 'max-age=31536000', 'Content-Encoding': 'gzip', 'Vary': 'User-Agent', 'Content-Type': 'application/json;charset=UTF-8', 'Content-Length': '85', 'Date': 'Mon, 18 Oct 2021 21:15:13 GMT', 'Keep-Alive': 'timeout=20', 'Connection': 'keep-alive'}
        response text = {"message":"Basic Authentication has been disabled on this instance."}

In [4]: j = JIRA('http://localhost:8080', token_auth=personal_access_token)

In [5]: j.projects()
Out[5]: [<JIRA Project: key='TEST', name='test', id='10000'>]

[adehad]

Thanks @ametzger , we were looking into this in #991 and were trying to see if we could get some unit testing setup: #991 (comment)

I was supposed to try having a go, but didn't get the chance. And I won't be free for a while again. Would you be able to try whipping something up?

[ametzger]

Sure thing! Sorry, missed that PR. I'll close this one as that one looks more idiomatic. Will see if there's something simple to put together.

[ametzger]

Closing: dupe of #991

[adehad]

No worries at all, feel free to reopen this PR if appropriate. (As we've been making several improvements to help contributors that probably haven't made its way to that original branch)