Bump Maven driven build to java 7

Change-Id: I8a8257029bf5dfe724bbaf1a0115a0597b3599d5

pom.xml

diff --git a/pom.xml b/pom.xml
index 434c0a2..fe0f552 100644
--- a/pom.xml
+++ b/pom.xml
@@ -56,8 +56,8 @@
         <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>
       </plugin>