pin to 0.18 because 0.19 is broken

[mshafer-NI]

flake8-import-order errors with

  File "/home/rfmibuild/myagent/_work/_temp/nidev-setup-oBKZYQJg-py3.8/lib/python3.8/site-packages/flake8_import_order/__init__.py", line 103, in visit_Import
    if node.col_offset == 0 or self._type_checking_import(node):
  File "/home/rfmibuild/myagent/_work/_temp/nidev-setup-oBKZYQJg-py3.8/lib/python3.8/site-packages/flake8_import_order/__init__.py", line 149, in _type_checking_import
    node.parent.test.value.id in {"t", "typing"}
AttributeError: 'Name' object has no attribute 'value'
"""

The above exception was the direct cause of the following exception:

Issue #212

[github-actions]

Thank you for contributing! 👋

[mshafer-NI]

I don't see a 0.18.3 on PyPI, not even a yanked version.

Fixed. Now pinning to <0.19.0