Suggested fix for test failures when script or fastpbkdf2 are installed and available

[gene-git]

If scrypt and/or fastpbkdf2 are installed , then 2 tests fail incorrectly:

FAILED test_crypto_digest.py::Pbkdf2Test::test_backends - AssertionError: assert ('fastpbkdf2' in ['hashlib-ssl']) == True
FAILED test_crypto_scrypt.py::BuiltinScryptTest::test_missing_backend - Failed: DID NOT RAISE <class 'passlib.exc.MissingBackendError'>
================== 2 failed, 2065 passed, 1536 skipped, 10 subtests passed in 103.42s (0:01:43)

This patch adds a check whether each module is installed:

fix-tests.patch

he issue arose in Archlinux