Cleanup headers

Author: jeroen

src/qrdetect.cpp

@@ -1,9 +1,4 @@
 #include "util.hpp"
-#include <opencv2/objdetect.hpp>
-#include <opencv2/imgcodecs.hpp>
-#include <opencv2/highgui/highgui.hpp>
-#include <opencv2/imgproc/imgproc.hpp>
-
 using namespace cv;
 
 // [[Rcpp::export]]