Eth-event

Added
- Decode events when the ABI contains indexed values but the log has None

Changed
- More expressive error messages when an event cannot be decoded from an incorrect number of topics

Added
- Anonymous and undecodable events can be returned without raising with the `allow_undecoded` kwarg
- MyPy typing
- Extensive docstrings

Changed
- `get_event_abi` is now `get_topic_map`
- `decode_event` is now `decode_log`
- `decode_trace` is now `decode_traceTransaction`
- decoding methods can no longer be passed a contract ABI - the ABI must first be converted using `get_topic_map`

Removed
- `get_topics` method
- `skip_anonymous` kwarg in decoder methods

- Support for Python 3.8

* Include components in decoded output for tuples

- Support for tuples (`ABIEncoderV2`)
- Update dependency versions
- Require python 3.6
- Added `get_log_topic`

* Properly handle arrays in events
* Verbose exceptions