dev_requirements.txt: bump minimum pytest versions to a working set Not all combinations of pytest-related packages seem to work. Trial-and-error lead to these combinations of minimum versions. Add a minimum bound to pytest-benchmark and pytest-localserver to help pip in figuring out a suitable combination with pytest, and also to allow testing minimum combinations in the future. Drop pytest-runner, which should not be needed unless when running tests directly from setup.py.

[pytest]
# only look for tests in kallithea/tests
python_files = kallithea/tests/**/test_*.py
addopts =
    # --verbose
    # show extra test summary info as specified by chars (f)ailed, (E)error, (s)skipped, (x)failed, (X)passed, (w)warnings.
    -rfEsxXw
    # Shorter scrollbacks; less stuff to scroll through
    --tb=short
    #
    --doctest-modules
    --doctest-ignore-import-errors