Python-jsonschema-objects

+ Fixes support for explicitly null types.
+ Fixes a typo in the documentation

+ Significantly improved documentation and added new tests
+ Added support for `oneOf` at the top level
+ Added support for circular references in schema definitions
+ bugfix: Fixed an issue with assignment of null values
+ bugfix: Fixed an issue setting properties with dictionary types

+ Adds support for the `default` keyword for literals.

Bugfixes:
+ Removes an extraneous __str__ method from classbuilder (h/t edwardcwang)
+ Ensures 'strict' is passed for definitions as well as main schema classes (h/t neyguvj)

**Bugfixes**

+ Fixes an issue where top level array item constraints weren't actually converted to class wrappers.

**Other Things**

+ Added a section to the README explaining how to create multiple top-level objects.

**Bugfixes**

+ Fixes an issue with opening schema files on systems without a default UTF encoding (65)
+ Updates equality comparisons to check class type before making assumptions about what methods exist (72)
+ Moves requirements into setup.py to better support library use. Also loosens specification of jsonschema as a requirement to allow more versions. (69)