test_timeout_check_call using sleep fails on WSL

[balarsen]

The test uses sleep to have a timeout. Sleep is broken on WSL and some Ubuntu per microsoft/WSL#4898

Maybe we just try...except or something if sleep works.

Minimal example to reproduce issue:

(python3) :~/git/spacepy/tests$ python test_toolbox.py test_timeout_check_call -v
This unreleased version of SpacePy is not supported by the SpacePy team.
test_timeout_check_call (unittest.loader._FailedTest) ... ERROR

======================================================================
ERROR: test_timeout_check_call (unittest.loader._FailedTest)
----------------------------------------------------------------------
AttributeError: module '__main__' has no attribute 'test_timeout_check_call'

----------------------------------------------------------------------
Ran 1 test in 0.001s

FAILED (errors=1)

Linux-4.4.0-18362-Microsoft-x86_64-with-debian-bullseye-sid
sys.version_info(major=3, minor=7, micro=7, releaselevel='final', serial=0)
numpy=1.19.1
scipy=1.5.2
matplotlib=3.2.2

Version of SpacePy

spacepy master f56b6d6

[balarsen]

(python3) :~/git/spacepy/tests$ sleep 2
sleep: cannot read realtime clock: Invalid argument

[jtniehof]

Duplicate of #344

Your example doesn't show this problem, but it's clear in the other.