Specify source compatibility mode to Java 7
diff --git a/pom.xml b/pom.xml
index 5b8df0c..0963968 100644
--- a/pom.xml
+++ b/pom.xml
@@ -64,8 +64,8 @@
         <artifactId>maven-compiler-plugin</artifactId>
         <version>2.3.2</version>
         <configuration>
-          <source>1.6</source>
-          <target>1.6</target>
+          <source>1.7</source>
+          <target>1.7</target>
           <encoding>UTF-8</encoding>
         </configuration>
         <executions>