Update pubspec.yaml

example/pubspec.yaml

@@ -21,7 +21,7 @@ dependencies:
   cupertino_icons: ^0.1.2
   flutter_screenutil:
     git:
-      url: git://github.com/openflutter/flutter_screenUtil
+      url: git://github.com/openflutter/flutter_screenutil
 dev_dependencies:
   flutter_test:
     sdk: flutter