#32 log.debug for stacktrace when growbros exception

src/main/java/hdm/mi/growbros/controllers/RestErrorHandler.java

@@ -18,6 +18,7 @@ public class RestErrorHandler extends ResponseEntityExceptionHandler {
     @ExceptionHandler(GrowBrosException.class)
     protected ResponseEntity<String> handleGrowBrosException(GrowBrosException e) {
         log.error("Handling exception '{}' : {} (Status code {})", e.getClass(), e.getMessage(), e.getStatusCode());
+        log.debug("Stacktrace:", e);
         return ResponseEntity.status(e.getStatusCode()).body(e.getMessage());
     }