ci fixes: flake8 + unittest missing module

10 jobs for pr/100 in 3 minutes and 34 seconds (queued for 7 seconds)
Name Stage Failure
failed
robotpkg-py-example-robot-data-buster Test
0% tests passed, 1 tests failed out of 1

Total Test time (real) = 41.47 sec

The following tests FAILED:
1 - py-load (Failed)
Errors while running CTest
make: *** [Makefile:110: test] Error 8
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
doc-coverage Test
Directory: .
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File Lines Exec Cover Missing
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TOTAL 0 0 --%
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$ gcovr -e CMakeFiles -r . --html --html-details -o ${CI_PROJECT_DIR}/coverage/index.html
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
robotpkg-py-example-robot-data-18.04 Test

Total Test time (real) = 25.26 sec

The following tests FAILED:
1 - py-load (Failed)
Errors while running CTest
make: *** [test] Error 8
Makefile:109: recipe for target 'test' failed
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
robotpkg-py-example-robot-data-ferrum Test

Total Test time (real) = 22.18 sec

The following tests FAILED:
1 - py-load (Failed)
Errors while running CTest
Makefile:128: recipe for target 'test' failed
make: *** [test] Error 8
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
robotpkg-py-example-robot-data-20.04 Test
0% tests passed, 1 tests failed out of 1

Total Test time (real) = 19.18 sec

The following tests FAILED:
1 - py-load (Failed)
Errors while running CTest
make: *** [Makefile:110: test] Error 8
Cleaning up file based variables
ERROR: Job failed: exit code 1