Revert changes to AutoValue documentation that talk about 1.6, until we can actually release 1.6.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189351166

Author: eamonnmcmanus

value/userguide/index.md

@@ -74,31 +74,21 @@ examples short and simple.
 Maven users should add the following to the project's `pom.xml` file:
 
 ```xml
-<dependency>
-  <groupId>com.google.auto.value</groupId>
-  <artifactId>auto-value-annotations</artifactId>
-  <version>1.6</version>
-</dependency>
 <dependency>
   <groupId>com.google.auto.value</groupId>
   <artifactId>auto-value</artifactId>
-  <version>1.6</version>
+  <version>1.5.4</version>
   <scope>provided</scope>
 </dependency>
 ```
 
-Alternatively, instead of using the `provided` scope, you can add the second
-dependency to the
-[`annotationProcessorPaths`](https://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html#annotationProcessorPaths)
-section.
-
 Gradle users should install the annotation processing plugin [as described in
 these instructions][tbroyer-apt] and then use it in the `build.gradle` script:
 
 ```groovy
 dependencies {
-  compileOnly "com.google.auto.value:auto-value-annotations:1.6"
-  apt         "com.google.auto.value:auto-value:1.6"
+  compileOnly "com.google.auto.value:auto-value:1.5.4"
+  apt         "com.google.auto.value:auto-value:1.5.4"
 }
 ```