Update Gradle Maven Publish Plugin to 0.6.0 (#132)

Author: vanniktech

build.gradle

@@ -9,7 +9,7 @@ buildscript {
     classpath 'com.gradle.publish:plugin-publish-plugin:0.10.0'
     classpath 'com.github.ben-manes:gradle-versions-plugin:0.17.0'
     classpath 'com.vanniktech:gradle-android-junit-jacoco-plugin:0.11.0'
-    classpath 'com.vanniktech:gradle-maven-publish-plugin:0.2.0'
+    classpath 'com.vanniktech:gradle-maven-publish-plugin:0.6.0'
   }
 }