Add production dependencies

node_modules/image-size/lib/readUInt.js

@@ -0,0 +1,11 @@
+'use strict';
+
+// Abstract reading multi-byte unsigned integers
+function readUInt (buffer, bits, offset, isBigEndian) {
+  offset = offset || 0;
+  var endian = !!isBigEndian ? 'BE' : 'LE';
+  var method = buffer['readUInt' + bits + endian];
+  return method.call(buffer, offset);
+}
+
+module.exports = readUInt;