Resolve test incompatibility with git v2.21.0

This fixes gitpython-developers#869

Author: jeking3

dockernose.sh

@@ -4,5 +4,7 @@ if [ -z "${PYVER}" ]; then
     PYVER=py37
 fi
 
+# remember to use "-s" if you inject pdb.set_trace() as this disables nosetests capture of streams
+
 tox -e ${PYVER} --notest
 PYTHONPATH=/src/.tox/${PYVER}/lib/python*/site-packages /src/.tox/${PYVER}/bin/nosetests --pdb $*

git/test/test_remote.py

@@ -638,7 +638,7 @@ def test_multiple_urls(self, rw_repo):
 
     def test_fetch_error(self):
         rem = self.rorepo.remote('origin')
-        with self.assertRaisesRegex(GitCommandError, "Couldn't find remote ref __BAD_REF__"):
+        with self.assertRaisesRegex(GitCommandError, "[Cc]ouldn't find remote ref __BAD_REF__"):
             rem.fetch('__BAD_REF__')
 
     @with_rw_repo('0.1.6', bare=False)