* Improve error message when not providing a value for key * Update packages/babel-plugin-transform-react-jsx/src/create-plugin.js Show location of attribute instead of only the path Co-authored-by: Huáng Jùnliàng <jlhwung@gmail.com> * Change error message to be less aggressive * Throw error when runtime is "classic" Co-authored-by: Huáng Jùnliàng <jlhwung@gmail.com>