Revert "Python 2.7 compatibility (atlassian-api#1087)"

This reverts commit 991e2c2.

Author: orent

atlassian/bamboo.py

@@ -369,7 +369,7 @@ def results(
             elements_key="results",
             element_key="result",
             label=label,
-            **params
+            **params,
         )
 
     def latest_results(

atlassian/bitbucket/cloud/repositories/__init__.py

@@ -254,7 +254,7 @@ def __init__(self, data, *args, **kwargs):
         self.__commits = Commits(
             "{}/commits".format(self.url),
             data={"links": {"commit": {"href": "{}/commit".format(self.url)}}},
-            **self._new_session_args
+            **self._new_session_args,
         )
         self.__default_reviewers = DefaultReviewers("{}/default-reviewers".format(self.url), **self._new_session_args)
         self.__issues = Issues("{}/issues".format(self.url), **self._new_session_args)

atlassian/rest_client.py

@@ -3,10 +3,7 @@
 from json import dumps
 
 import requests
-try:
-    from oauthlib.oauth1 import SIGNATURE_RSA_SHA512 as SIGNATURE_RSA
-except ImportError:
-    from oauthlib.oauth1 import SIGNATURE_RSA_SHA512
+from oauthlib.oauth1 import SIGNATURE_RSA_SHA512
 from requests import HTTPError
 from requests_oauthlib import OAuth1, OAuth2
 from six.moves.urllib.parse import urlencode
@@ -106,7 +103,7 @@ def _create_oauth_session(self, oauth_dict):
         oauth = OAuth1(
             oauth_dict["consumer_key"],
             rsa_key=oauth_dict["key_cert"],
-            signature_method=SIGNATURE_RSA,
+            signature_method=SIGNATURE_RSA_SHA512,
             resource_owner_key=oauth_dict["access_token"],
             resource_owner_secret=oauth_dict["access_token_secret"],
         )