hg: handle Mercurial RepoError correctly in is_valid_repo_uri RepoError would be leaked by is_valid_repo_uri. Now, when for example validating an ssh URL without having the ssh client binary, it will be shown/logged as: remote: /bin/sh: ssh: command not found 2020-03-17 17:28:53.907 WARNI [kallithea.model.validators] validation of clone URL 'ssh://no-ssh.com/' failed: Mercurial RepoError: no suitable response from remote hg and shown in the UI as 'Invalid repository URL'.

[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