Cleanly catch keyboard interrupts during tests

When running the inventory tests on a development machine, using ctrl-c
to send sigint should gracefully finish the current test and clean up
the workspace (tests/inventory).

While most of our tests are well-behaved, without the catchbreak=True
option, sometimes the code would be interrupted in between file creation
and cleanup. Additionally, tearDownModule was never called, leaving
behind inventory/openstack_user_config.yml

This change allows the current test to finish, it's teardown methods to
run, and finally the tearDownModule function to execute, leaving behind
a clean workspace. Only the tests that directly touch the filesystem
were changed.

While this is not impactful for gate tests, it improves quality of life
for developers.

Change-Id: I992e514e58958264d90faab7bc295d6d8e89f039

tests/test_filesystem.py

@@ -102,4 +102,4 @@ class TestMultipleRuns(unittest.TestCase):
 
 
 if __name__ == '__main__':
-    unittest.main()
+    unittest.main(catchbreak=True)

tests/test_inventory.py

@@ -1400,4 +1400,4 @@ class TestInventoryGroupConstraints(unittest.TestCase):
 
 
 if __name__ == '__main__':
-    unittest.main()
+    unittest.main(catchbreak=True)

tests/test_manage.py

@@ -127,4 +127,4 @@ class TestRemoveIpfunction(unittest.TestCase):
 
 
 if __name__ == '__main__':
-    unittest.main()
+    unittest.main(catchbreak=True)