Add action and reducer

Author: Hombre2014

app/javascript/components/Greeting.js

@@ -1,18 +1,36 @@
 import React from "react";
 import PropTypes from "prop-types";
+import { connect } from "react-redux";
+import { createStructuredSelector } from "reselect";
+
+const GET_GREETINGS_REQUEST = "GET_GREETINGS_REQUEST";
+
+function getGreetings() {
+  console.log('getGreetings(), Action!');
+  return {
+    type: 'GET_GREETINGS_REQUEST'
+  };
+};
 
 class Greeting extends React.Component {
   render () {
     return (
       <React.Fragment>
         Greeting Message: {this.props.greetingMessage}
+        <button className="btn btn-more" onClick={() => this.props.getGreetings()}>Get another greeting</button>
       </React.Fragment>
     );
   }
 }
 
+const structuredSelector = createStructuredSelector({
+  greetings: state => state.greetings,
+});
+
+const mapDispatchToProps = { getGreetings };
+
 Greeting.propTypes = {
   greetingMessage: PropTypes.string
 };
 
-export default Greeting;
+export default connect(structuredSelector, mapDispatchToProps)(Greeting);