Non serializable objects shall be handled by default() function

[jrief]

The Django docs state: https://docs.djangoproject.com/en/1.7/topics/serialization/#serialization-formats-json

REST framework does it as well: https://github.com/tomchristie/django-rest-framework/blob/4248a8d3fc725d9ae3fe7aaaad7ee12479ab07ab/rest_framework/utils/encoders.py#L21

we could even consider to support more types inside that default() method.

[coveralls]

Coverage decreased (-0.02%) to 90.92% when pulling 0a837b5 on jrief:SafeJSONEncoder_default into eff8c00 on divio:develop.

[coveralls]

Coverage decreased (-0.02%) to 90.92% when pulling 0a837b5 on jrief:SafeJSONEncoder_default into eff8c00 on divio:develop.

[coveralls]

Coverage decreased (-0.02%) to 90.92% when pulling 0a837b5 on jrief:SafeJSONEncoder_default into eff8c00 on divio:develop.

[coveralls]

Coverage decreased (-0.1%) to 90.813% when pulling 0a837b5 on jrief:SafeJSONEncoder_default into eff8c00 on divio:develop.

[yakky]

Thanks @jrief