CHANGELOG: add return type annotations to test functions (#43)

Author: dannywillems

CHANGELOG.md

@@ -29,6 +29,8 @@ and this project adheres to
 - Fix leaked file handles in tests using context managers ([b66a6f5], [#25])
 - Fix `Decimal.normalize()` stripping trailing zeros, breaking round-trip
   serialization; add regression test ([28c76f1], [0130743], [#28])
+- Add return type annotations to test functions for mypy compliance
+  ([cd74b55], [#43])
 - Fix typo in test name: `test_l9events_form_ip4scout` ->
   `test_l9events_from_ip4scout` ([0d8736e], [#27])
 
@@ -154,6 +156,7 @@ and this project adheres to
 
 <!-- Commit links -->
 
+[cd74b55]: https://github.com/LeakIX/l9format-python/commit/cd74b55
 [0130743]: https://github.com/LeakIX/l9format-python/commit/0130743
 [28c76f1]: https://github.com/LeakIX/l9format-python/commit/28c76f1
 [b66a6f5]: https://github.com/LeakIX/l9format-python/commit/b66a6f5
@@ -230,3 +233,4 @@ and this project adheres to
 [#33]: https://github.com/LeakIX/l9format-python/issues/33
 [#25]: https://github.com/LeakIX/l9format-python/issues/25
 [#35]: https://github.com/LeakIX/l9format-python/issues/35
+[#43]: https://github.com/LeakIX/l9format-python/issues/43