Short message notification when project contains only one module.

Automatically use short message description because with full message
build time information is duplicated.

src/main/java/com/github/jcgay/maven/notifier/AbstractCustomEventSpy.java

@@ -58,12 +58,20 @@ protected Status getBuildStatus(MavenExecutionResult result) {
     }
 
     protected String buildNotificationMessage(MavenExecutionResult result) {
-        if (configuration.isShortDescription()) {
+        if (shouldBuildShortDescription(result)) {
             return buildShortDescription(result);
         }
         return buildFullDescription(result);
     }
 
+    private boolean shouldBuildShortDescription(MavenExecutionResult result) {
+        return configuration.isShortDescription() || hasOnlyOneModule(result);
+    }
+
+    private boolean hasOnlyOneModule(MavenExecutionResult result) {
+        return result.getTopologicallySortedProjects().size() == 1;
+    }
+
     protected String buildShortDescription(MavenExecutionResult result) {
         if (getBuildStatus(result) == Status.SUCCESS) {
             StringBuilder builder = new StringBuilder("Built in: ");
@@ -95,7 +103,7 @@ private String buildFullDescription(MavenExecutionResult result) {
 
     protected String buildTitle(MavenExecutionResult result) {
         StringBuilder builder = new StringBuilder().append(result.getProject().getName());
-        if (!configuration.isShortDescription()) {
+        if (!shouldBuildShortDescription(result)) {
             builder.append(" [")
                    .append(stopwatch.elapsedTime(TimeUnit.SECONDS))
                    .append("s]");