Preparing for new version: v0.2.0

If calibration is finally reliable, let's update the version!

ampel-firmware/util.h

@@ -38,7 +38,7 @@ class Ampel {
 private:
   static void showFreeSpace();
 public:
-  const char *version = "v0.1.1"; // Update manually after significant changes.
+  const char *version = "v0.2.0"; // Update manually after significant changes.
   const char *board;
   const char *sensorId;
   uint32_t max_loop_duration;