Update autovalue to 1.6.

This is required to build with Java 9.

build.gradle

@@ -96,7 +96,8 @@ subprojects {
     dependencies {
         compile group: 'com.google.code.findbugs', name: 'jsr305', version: '3.0.1'
         compile group: 'com.squareup.dagger', name: 'dagger-compiler', version: '1.2.5'
-        compile group: 'com.google.auto.value', name: 'auto-value', version: '1.3'
+        compile group: 'com.google.auto.value', name: 'auto-value', version: '1.6'
+        compile group: 'com.google.auto.value', name: 'auto-value-annotations', version: '1.6'
 
         compile group: 'org.slf4j', name: 'slf4j-api', version:'1.7.21'
         compile group: 'com.squareup.dagger', name: 'dagger', version: '1.2.5'