Specify that Kafka 0.10.0 is not supported

Author: dasch

README.md

@@ -95,7 +95,7 @@ This library is targeting Kafka 0.9 with the v0.4.x series and Kafka 0.10 with t
 
 - **Kafka 0.8:** Full support for the Producer API in ruby-kafka v0.4.x, but no support for consumer groups. Simple message fetching works.
 - **Kafka 0.9:** Full support for the Producer and Consumer API in ruby-kafka v0.4.x.
-- **Kafka 0.10:** Full support for the Producer and Consumer API in ruby-kafka v0.5.x.
+- **Kafka 0.10:** Full support for the Producer and Consumer API in ruby-kafka v0.5.x. Note that the _must_ run version 0.10.1 or higher of Kafka due to limitations in 0.10.0.
 - **Kafka 0.11:** Everything that works with Kafka 0.10 should still work, but so far no features specific to Kafka 0.11 have been added.
 
 This library requires Ruby 2.1 or higher.