Dbtools

* Add Python 3 support

* Include VERSION.txt in pip package

* Add sphinx documentation
* Add Travis CI support
* Add `list_tables` method to `Table` class
* Make column name/primary key/autoincrement parsing more robust
* Check if SQLite table exists on `Table` initialization
* Allow tests to be run from within `tests` directory

* Fix `pip install` installation bug

* Fix an issue in `Table` initialization from `DataFrame` (5)
* Allow `Table` initialization from a dictionary of list of
dictionaries (2)
* Create testing metaclass to modify test case docstrings to include
class name
* Add `Makefile` and other minor installation modifications

* Add `setup.py` installation support (4)
* Allow `Table` initialization from a pandas `DataFrame` (1)
* Fix misues of autoincrement/primary key
* Add `Table.exists` class method