added lowercase stage

src/main/java/teetime/stage/string/ToLowerCase.java

+package teetime.stage.string;
+
+import teetime.framework.AbstractConsumerStage;
+import teetime.framework.OutputPort;
+
+/**
+ * Receives a string and passes it on to the next stage only with lower case letters.
+ *
+ * @author Nelson Tavares de Sousa
+ *
+ */
+public class ToLowerCase extends AbstractConsumerStage<String> {
+
+	private final OutputPort<String> outputPort = this.createOutputPort();
+
+	@Override
+	protected void execute(final String element) {
+		outputPort.send(element.toLowerCase());
+
+	}
+
+}