remove distutils (#463)

* remove distutils

* should be OK

Author: ocefpaf

cf_xarray/tests/__init__.py

@@ -1,10 +1,10 @@
 import importlib
 import re
 from contextlib import contextmanager
-from distutils import version
 
 import dask
 import pytest
+from packaging import version
 
 
 @contextmanager
@@ -60,7 +60,7 @@ def LooseVersion(vstring):
     # Our development version is something like '0.10.9+aac7bfc'
     # This function just ignored the git commit id.
     vstring = vstring.split("+")[0]
-    return version.LooseVersion(vstring)
+    return version.parse(vstring)
 
 
 has_cftime, requires_cftime = _importorskip("cftime")