[enhancement] use react-s-alert instead of toastr to alarm some message to user

[enhancement] use react-s-alert instead of toastr to alarm some message to user

Not only the features of `toastr` are almost exactly provided by `react-s-alert` but also it doesn't depend on `jQuery`.

I used `react-s-alert` in my client's project and it was easy to use.

Demo: http://react-s-alert.jsdemo.be/
Github: https://github.com/juliancwirko/react-s-alert-demo