only use default at __init__
split to_db (renamed to_primitive)

to allow different behaviour depending on if we're serialising for the
db or for not
Notify ofb on travis builds
Order results to make test always pass
Merge pull request #55 from onefinestay/travis-notifications

Notify ofb on travis builds
Merge remote-tracking branch 'origin/master' into to_primitive
better test
add docstring
Merge pull request #56 from onefinestay/to_primitive

To primitive
None->None in to_primitive as well
prefer positive tests
Merge pull request #58 from onefinestay/to_primitive

To primitive
Merge branch 'master' into 817-metaclass-refactor

Conflicts:
	kaiso/persistence.py
	kaiso/queries.py
	kaiso/serialize.py
	kaiso/types.py
	test/test_dynamic_types.py
	test/test_serialize.py