Update readme for InfluxDB 1.8+ (#81)

Author: kelseiv

README.rst

@@ -36,7 +36,7 @@ influxdb-client-python
 
 InfluxDB 2.0 python client library.
 
-**Note: This library is for use with InfluxDB 2.x. For connecting to InfluxDB 1.x instances, please use the** `influxdb-python <https://github.com/influxdata/influxdb-python>`_.
+**Note: Use this client library with InfluxDB 2.x and InfluxDB 1.8+. For connecting to InfluxDB 1.7 or earlier instances, use the `influxdb-python <https://github.com/influxdata/influxdb-python>` client library.**
 
 InfluxDB 2.0 client features
 ----------------------------
@@ -884,4 +884,4 @@ Bug reports and pull requests are welcome on GitHub at `https://github.com/influ
 License
 -------
 
-The gem is available as open source under the terms of the `MIT License <https://opensource.org/licenses/MIT>`_.
+The gem is available as open source under the terms of the `MIT License <https://opensource.org/licenses/MIT>`_.