Update javadoc target version
diff --git a/pom.xml b/pom.xml
index b79844a..68400dd 100644
--- a/pom.xml
+++ b/pom.xml
@@ -426,7 +426,7 @@
                         <artifactId>maven-javadoc-plugin</artifactId>
                         <version>2.9.1</version>
                         <configuration>
-                            <source>1.5</source>
+                            <source>1.7</source>
                         </configuration>
                         <executions>
                             <execution>