Resolve issue #20 by moving delay after 2 second read check to make read return quickly.

examples/DHTtester/DHTtester.ino

@@ -25,6 +25,9 @@ void setup() {
 }
 
 void loop() {
+  // Wait a few seconds between measurements.
+  delay(2000);
+
   // Reading temperature or humidity takes about 250 milliseconds!
   // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
   float h = dht.readHumidity();