Improvements
- JSON encoder now defaults to string encoding of types not handled by the default encoder (such as datetime). Previously, these would result in a `TypeError` being raised during event serialization, causing the event to be dropped.
Security Updates
- Updates example Django app to 1.8.19 in response to [CVE-2017-7233](https://nvd.nist.gov/vuln/detail/CVE-2017-7233).