tests: Unset PAGER env when testing fallback

Prior to this commit, the test test_echo_via_pager_env_default will
fail when $PAGER is set to /usr/bin/less (or anything other than
"less").  Use unittest.mock to unset the environment variable during
the test.

Author: 00-matt

tests/test_utils.py

@@ -75,6 +75,7 @@ def test_echo_via_pager_env_PAGER(mock_inner, mock_tabulate, mock_config):
 @mock.patch.object(utils, 'git_config', return_value=None)
 @mock.patch.object(utils, '_tabulate')
 @mock.patch.object(utils, '_echo_via_pager')
+@mock.patch.dict(os.environ, {'PAGER': ''})
 def test_echo_via_pager_env_default(mock_inner, mock_tabulate, mock_config):
     utils.echo_via_pager('test', ('foo',), None)