upgrade javadoc to 3.0.1 (#2454)

Author: jerrick-zhu

pom.xml

@@ -115,7 +115,7 @@
         <maven_deploy_version>2.8.2</maven_deploy_version>
         <maven_compiler_version>3.6.0</maven_compiler_version>
         <maven_source_version>3.0.1</maven_source_version>
-        <maven_javadoc_version>3.0.0</maven_javadoc_version>
+        <maven_javadoc_version>3.0.1</maven_javadoc_version>
         <maven_jetty_version>6.1.26</maven_jetty_version>
         <maven_checkstyle_version>3.0.0</maven_checkstyle_version>
         <maven_jacoco_version>0.8.1</maven_jacoco_version>