Features
1. [358](https://github.com/influxdata/influxdb-client-python/pull/358): Update management API:
- `BucketsApi` - add possibility to: `update`
- `OrganizationsApi` - add possibility to: `update`
- `UsersApi` - add possibility to: `update`, `delete`, `find`
1. [356](https://github.com/influxdata/influxdb-client-python/pull/356): Add `MultiprocessingWriter` to write data in independent OS process
Bug Fixes
1. [359](https://github.com/influxdata/influxdb-client-python/pull/359): Correct serialization empty columns into LineProtocol [DataFrame]