Integrate tox into setup.py. Move install_requires to metadata.
Pylint.
Recursive __table_args__,  __mapper_args__; added __enum_args__
Merge pull request #11 from seth-p/table_and_mapper_args

Made __table_args__ & __mapper_args__ recursive functions.
Apply consistent spacing.
Remove declared_attr integration with table args and mapper args due to issue where arg values leak into other classes.
Re-implement making ModelBase's __table_args__ and __mapper_args__ inheritable.
Pylint.
Add Seth P. to contributors.
Ensure table args are unique after combining merged args with local args.
Remove duplicate assignment.
Release v1.4.0.