Use LooseVersion from looseversion rather than distutils

setup.cfg

@@ -36,6 +36,7 @@ setup_requires =
     setuptools_scm
     pytest-runner
 install_requires =
+    looseversion
     decopatch
     makefun>=1.9.5
     # note: pytest, too :)

src/pytest_cases/common_pytest_marks.py

@@ -5,7 +5,7 @@
 import itertools
 
 import warnings
-from distutils.version import LooseVersion
+from looseversion import LooseVersion
 
 try:  # python 3.3+
     from inspect import signature

tests/cases/issues/test_issue_246.py

@@ -1,4 +1,4 @@
-from distutils.version import LooseVersion
+from looseversion import LooseVersion
 
 import pytest
 from pytest_cases import parametrize_with_cases