This PR adds new assert_ methods to functional/test_framework/util.py:
- assert_not_equal
- assert_less_than
- assert_less_than_or_equal
Additionally, the example_test.py got a new method test_asserts to showcase them. I have searched for test-the-test-showcases but couldn't find any, hence the expansion of example_test.py
The motivation for this PR is based on my own experience with writing functional tests. From time to time I ran into situations where I wanted to test for something that is not equal X or less than X, but as only assert_equal respective assert_greater_than were available, I had to negate expressions first, before testing them with available asserts:
assert_equal(negated_expression, False)
assert_equal(greater_than_expression, False)