case insensitive glob

raspberry-environment/display.py

@@ -235,6 +235,9 @@ if __name__ == '__main__':
       list_of_files = glob.glob('/mnt/*.png')
       list_of_files.extend(glob.glob('/mnt/*.jpg'))
       list_of_files.extend(glob.glob('/mnt/*.bmp'))
+      list_of_files.extend(glob.glob('/mnt/*.PNG'))
+      list_of_files.extend(glob.glob('/mnt/*.JPG'))
+      list_of_files.extend(glob.glob('/mnt/*.BMP'))
 
       if list_of_files:
         latest_file = max(list_of_files, key=os.path.getctime)