Updated .travis.yml

Reused the one from iPOPO, without coveralls
Merge pull request #5 from dawryn/master

Dump Custom objects with slots
Merge pull request #7 from dawryn/master

Dump user defined types with handler functions (can be used to override dump of built-in types)
Small code review with pylint and pep8
Added configuration for coverage

- added coverage configuration file
- added coverage folder to .gitignore
Added push to coveralls
New structure of tests

Replaced the single-module tests.py to a tests package.
=> Simplifies the writing of new tests
Added tests from jsonclass

- Check de/serialization of various types
- TODO: add support for inherited types using __slots__
Add unittest2 in Python 2.6 Tox tests
Avoid using relative imports in tests

This messes with "unittest discover"
Corrected README

- updated commands to run tests (unittest discover)
- added some badges
Added configuration file for wheel
Version updated to 0.1.7
Enhance support for bean inheritance

Replaced the __dict__ and __slots__ trick by inspect.getmembers().
Beans inheriting fields from parent classes using __dict__ and/or __slots__
are now supported.
Corrected call to inspect.getmodule for some cases

It was possible that for some objects, mainly C++-side objects, inspect.getmodule() returned None.
New version of dump(), based on __bases__

- Doesn't rely on inspect.getmembers() anymore (too slow)
- Supports inheritance of beans using __dict__ and __slots__
Added a test for custom type-based serializers
Recursive search for __slots__: bean inheritance is fully handled now
Added tests for a two-levels inheritance
The dictionary given to load() keeps its __jsonclass__ attribute