Add Maven enforcer plugin in parent POM to check against minimum 1.7 JDK
diff --git a/pom.xml b/pom.xml
index d35f0b6..787febf 100644
--- a/pom.xml
+++ b/pom.xml
@@ -570,6 +570,25 @@
               <xmlOutput>true</xmlOutput>
            </configuration>
       </plugin>
+
+      <plugin>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>enforce-java</id>
+            <goals>
+              <goal>enforce</goal>
+            </goals>
+            <configuration>
+              <rules>
+                <requireJavaVersion>
+                  <version>1.7.0</version>
+                </requireJavaVersion>
+              </rules>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
     </plugins>
   </build>