Close notifier in *Example

Author: jcgay

send-notification/src/test/java/NotifySendExample.java

@@ -32,5 +32,6 @@ public static void main(String[] args) {
             .build();
 
         notifier.send(notification);
+        notifier.close();
     }
 }

send-notification/src/test/java/SimpleNotificationCenter.java

@@ -31,5 +31,6 @@ public static void main(String[] args) {
             .build();
 
         notifier.send(notification);
+        notifier.close();
     }
 }

send-notification/src/test/java/TerminalNotifierExample.java

@@ -31,5 +31,6 @@ public static void main(String[] args) {
             .build();
 
         notifier.send(notification);
+        notifier.close();
     }
 }