Write more proper unit tests that could replace current integration tests

[okurz]

motivation

openqa_review has 100% statement and branch coverage so it's easy to start hacking and see how it behaves. The current tests are "integration tests" that rely on downloaded html source files and compare the generated result against reference reports in markdown. This is a complete testing approach but the two main limitations are:

• tests can be slow more than 1 second for a complete test run can be considered too much for such a simple project
• not so helpful test failures if tests fail the main problem shown is that the generated report does not look like the reference which is not helpful when trying to work on low-level internal functions.

suggestion

More proper unit tests (could also be doctests) should be added.