tests: silence coverage error

Signed-off-by: Stephen L. <[email protected]>

TODO.md

@@ -4,7 +4,7 @@ PyFileFixity Todo
 TODO
 --------
 
-000000000. Urgent bugfixes: code coverage is varying because unit test is non-deterministic somehow! Need to fix this issue! Maybe a difference between platforms (eg, of data encoding?) + Need to fix encoding error, see issue #7 on GitHub (and may be related to the previous point)
+000000000. Urgent bugfixes: code coverage is varying because unit test is non-deterministic somehow! Need to fix this issue! Maybe a difference between platforms (eg, of data encoding?) + Need to fix encoding error, see issue #7 on GitHub (and may be related to the previous point). See https://community.codecov.com/t/reported-change-in-coverage-when-no-code-changes-made/1346/9 and https://docs.codecov.com/docs/unexpected-coverage-changes
 
 00000000. Rework routines with asyncio https://github.com/SuperFastPython/PythonAsyncioJumpStart
 

codecov.yml

@@ -0,0 +1,7 @@
+coverage:
+  status:
+    project:
+      default:
+        # basic
+        target: auto
+        removed_code_behavior: fully_covered_patch  # see: https://about.codecov.io/blog/new-codecov-setting-removed-code-behavior/