Maven POM: update javadoc plugin version.

Author: carlosame

pom.xml

@@ -62,7 +62,7 @@
 		<plugin>
 			<groupId>org.apache.maven.plugins</groupId>
 			<artifactId>maven-javadoc-plugin</artifactId>
-			<version>3.1.0</version>
+			<version>3.1.1</version>
 			<configuration>
 				<source>7</source>
 				<quiet>true</quiet>
@@ -118,7 +118,7 @@
 		<plugin>
 			<groupId>org.apache.maven.plugins</groupId>
 			<artifactId>maven-javadoc-plugin</artifactId>
-			<version>3.1.0</version>
+			<version>3.1.1</version>
 			<configuration>
 			  <reportOutputDirectory>${project.build.directory}/doc</reportOutputDirectory>
 			  <destDir>api</destDir>