Add example data and tests

Change-Id: Ife7b03d33607ec6c27da39b783e66e28f6496bbc
diff --git a/script/derekovecs-server b/script/derekovecs-server
index f17e92d..faf579a 100755
--- a/script/derekovecs-server
+++ b/script/derekovecs-server
@@ -343,7 +343,8 @@
          return $str;
       });
 
-hook(
+if(app->config->{Piwik} && app->config->{Piwik}->url) {
+  hook(
       after_render => sub {
         my $c = shift;
 
@@ -370,7 +371,8 @@
 
         # $c->app->log->info("PIWIK: counted.");
       }
-);
+  );
+}
 
 app->renderer->paths([app->home->rel_file('../templates')]);
 app->start;