support/testing: add new test for python-urllib3

Importing urllib3 already allows us to check that for example zlib can
be loaded at runtime.

For good measure, also create the PoolManager object mentioned in the
user guide ([1]), and check that we can normalize a URL like it is
done in urllib3's 'test/test_util.py'.

[1]: https://urllib3.readthedocs.io/en/stable/user-guide.html

Signed-off-by: Raphaël Mélotte <raphael.melotte@mind.be>
Signed-off-by: Julien Olivain <ju.o@free.fr>

support/testing/tests/package/sample_python_urllib3.py

@@ -0,0 +1,9 @@
+# Check that we can import urllib3 even if we don't use all of it:
+import urllib3
+
+# Just check that we can create a PoolManager:
+http = urllib3.PoolManager()
+
+# Check if we can normalize URLs:
+assert urllib3.util.url.parse_url("HTTPS://Example.Com/?Key=Value").url \
+    == "https://example.com/?Key=Value"