MINOR: Update README to specify Gradle 4.6 as the minimum required version
uses `annotationProcessor`, which was introduced in Gradle 4.6.
Reviewers: Ismael Juma
@@ -4,7 +4,7 @@ See our [web site](http://kafka.apache.org) for details on the project.
You need to have [Gradle](http://www.gradle.org/installation) and [Java](http://www.oracle.com/technetwork/java/javase/downloads/index.html) installed.
-Kafka requires Gradle 4.5 or higher.
+Kafka requires Gradle 4.6 or higher.
Java 8 should be used for building in order to support both Java 8 and Java 10 at runtime.
