Merge pull request #72 from nylas/tasdrake/sc-72693/pykerberos-instal…

…lation-fails-on-osx-12

Update requests-kerberos requirement.

setup.py

@@ -40,7 +40,8 @@ def read(file_name):
     keywords='Exchange EWS autodiscover',
     install_requires=['requests>=2.7', 'requests_ntlm>=0.2.0', 'dnspython>=1.14.0', 'pytz', 'lxml>3.0',
                       'cached_property', 'future', 'six', 'tzlocal', 'python-dateutil', 'pygments', 'defusedxml',
-                      'isodate', 'requests_kerberos', "typing; python_version < '3.5'"],
+                      'isodate', 'requests-kerberos @ git+https://github.com/nylas/requests-kerberos', 
+                      "typing; python_version < '3.5'"],
     packages=['exchangelib'],
     tests_require=['PyYAML', 'requests_mock', 'psutil'],
     python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",