* Finally add a CHANGELOG.md to communicate breaking changes (#598)
* Test multiple versions of InfluxDB in travis
* Add SHARD DURATION parameter to retention policy create/alter
* Update POST/GET requests to follow verb guidelines from InfluxDB
  documentation
* Update test suite to support InfluxDB v1.3.9, v1.4.2, and v1.5.4
* Fix performance degradation when removing NaN values via line
  protocol (#592)
* Dropped support for Python3.4