Migrate to pytest features

[kurtmckee]

This PR introduces the following changes:

• Migrate the test suite to use pytest features
• Address a duplicated test name in test_Exceptions.py: test_ListReadersException.
  The duplicate tests have been merged.

Most of this work was mechanical:

• Remove unittest.TestCase subclass definition lines
• De-dent the class methods
• Remove references to self in the function parameters
• Use regular expressions to search and replace assertions:
  • self.assertEqual(x, y) -> assert x == y
  • self.assertRaises -> pytest.raises
  • self.assertFalse(x) -> assert x is False
  • self.assertIn(x, y) -> assert x in y

Some long strings were wrapped to prepare for the possibility of using code formatters in the future.

STDOUT capture code was replaced with the pytest capsys fixture, which simplified the code in test_ATR.py.

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This PR prepares for the possibility of consolidating the live tests in src/smartcard/test/ together with the overall test suite, and using pytest features to control whether the live tests run or not.

This is only a possibility, not a guarantee, but migrating from unittest code to pytest code helps pave the way.

[coveralls]

coverage: 60.337% (+0.3%) from 60.037%
when pulling a9beece on kurtmckee:migrate-to-pytest
into 1baa8ea on LudovicRousseau:master.

[LudovicRousseau]

Have you migrated the code by hand?
Or with an automatic tool?

[kurtmckee]

This was done by hand (and with some search and replace) unfortunately.

[LudovicRousseau]

Merged in 1e3c419

Thanks