let the OS pick an available port, to avoid what appear to be timing issues causing multiple browsers to choose the same port

tests/test_units.py

@@ -25,7 +25,6 @@ import brozzler
 import brozzler.chrome
 import socket
 import logging
-import psutil
 import yaml
 
 @pytest.fixture(scope='module')
@@ -57,23 +56,6 @@ def test_robots(httpd):
     site = brozzler.Site(seed=url, user_agent='im/a bAdBOt/uh huh')
     assert not brozzler.is_permitted_by_robots(site, url)
 
-def test_find_available_port():
-    x = brozzler.chrome.Chrome(None, None)
-    try:
-        psutil.net_connections(kind='tcp')
-    except psutil.AccessDenied:
-        logging.warn(
-                'skipping _find_available_port() test because '
-                'psutil.net_connections(kind="tcp") raised AccessDenied')
-        return
-    assert x._find_available_port(9800) == 9800
-    sock = socket.socket()
-    sock.bind(('localhost', 9800))
-    sock.listen(0)
-    assert x._find_available_port(9800) >= 9990
-    sock.close()
-    assert x._find_available_port(9800) == 9800
-
 def test_scoping():
     test_scope = yaml.load('''
 max_hops: 100