Test suite doesn't work on macOS

[jdanford]

Same behavior on Python 3.5 and 3.10

EE/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/base_events.py:685: ResourceWarning: unclosed event loop <_UnixSelectorEventLoop running=False closed=False debug=False>
Exception ignored in: <function BaseEventLoop.__del__ at 0x1015b3400>
Traceback (most recent call last):
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/base_events.py", line 687, in __del__
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/unix_events.py", line 68, in close
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/selector_events.py", line 87, in close
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/selector_events.py", line 94, in _close_self_pipe
AttributeError: '_UnixSelectorEventLoop' object has no attribute '_ssock'

======================================================================
ERROR: test_many_pings (aioping.tests.test_aioping.TestAioping)
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Traceback (most recent call last):
  File "/Users/jsd/Developer/aioping/aioping/tests/test_aioping.py", line 45, in test_many_pings
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/base_events.py", line 646, in run_until_complete
  File "/Users/jsd/Developer/aioping/aioping/tests/test_aioping.py", line 31, in _do_ping
  File "/Users/jsd/Developer/aioping/aioping/__init__.py", line 283, in ping
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/socket.py", line 232, in __init__
OSError: [Errno 24] Too many open files

======================================================================
ERROR: test_verbose_ping (aioping.tests.test_aioping.TestAioping)
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Traceback (most recent call last):
  File "/Users/jsd/Developer/aioping/aioping/tests/test_aioping.py", line 14, in test_verbose_ping
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/events.py", line 782, in new_event_loop
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/events.py", line 673, in new_event_loop
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/unix_events.py", line 64, in __init__
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/asyncio/selector_events.py", line 53, in __init__
  File "/Users/jsd/.pyenv/versions/3.10.6/lib/python3.10/selectors.py", line 512, in __init__
OSError: [Errno 24] Too many open files

----------------------------------------------------------------------
Ran 2 tests in 0.030s

FAILED (errors=2)