Use Java 7

Change-Id: Icbc0439251be377483c17ba07f3a63246755b911
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

pom.xml

diff --git a/pom.xml b/pom.xml
index 3845fdd..b504c52 100644
--- a/pom.xml
+++ b/pom.xml
@@ -59,8 +59,8 @@
         <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>