Bump Java to 1.7

Change-Id: I9111e21e6186214483a07a3a2b4672a054fe721d

pom.xml

diff --git a/pom.xml b/pom.xml
index 8d681ab..2d8e8a6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -126,8 +126,8 @@
           <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>