set BREE to JAva 1.7

examples/org.yakindu.sct.examples/META-INF/MANIFEST.MF

@@ -7,5 +7,5 @@ Bundle-Activator: org.yakindu.sct.ui.examples.Activator
 Bundle-Vendor: statecharts.org
 Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.emf.common.ui;bundle-version="2.7.0"
-Bundle-RequiredExecutionEnvironment: JavaSE-1.6
+Bundle-RequiredExecutionEnvironment: JavaSE-1.7
 Bundle-ActivationPolicy: lazy