argschema_utilities `check_write_access` functions don't work properly on Windows

[njmei]

Describe the bug
check_write_access_overwrite and check_write_access (at allensdk.brain_observatory.argschema_utilities) do not work properly on Windows systems.

To Reproduce

from allensdk.brain_observatory.argschema_utilities import check_write_access_overwrite
bad_path = "//\/\/\?/\/some_invalid_filepath/file.txt"
check_write_access(bad_path)

Expected behavior
check_write_access() should throw an exception.

Actual Behavior
check_write_access returns True

Environment (please complete the following information):

• OS & version: Windows 10
• Python version: 3.7
• AllenSDK version: 1.0.1

Additional context
Fixing this is more of a nice to have as all pipelines that use the argschema_utilities.py module are run on Linux systems.

There are tests for check_write_access but it looks like they currently get skipped for Windows systems.