Bump java compat version (reverted from commit 0203252b6398cbf6ae9dc5c78c25d32e8849d927)

pom.xml

@@ -53,8 +53,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>2.3.2</version>
                 <configuration>
-                    <source>1.7</source>
-                    <target>1.7</target>
+                    <source>1.6</source>
+                    <target>1.6</target>
                     <excludes>
                     </excludes>
                 </configuration>