Add ui for answers from source

web/src/components/IntentDetails.js

@@ -1,5 +1,6 @@
 import React, { Component } from 'react';
 import {Button, SVGIcon, TextField} from 'react-md';
+import AnswerSource from './AnswerSource.js';
 import '../css/components/IntentDetails.css';
 import '../css/Common.css';
 import {QUESTION_MAX_LENGTH, ANSWER_MAX_LENGTH, INTENT_NAME_MAX_LENGTH, INTENT_EXPLANATION_MAX_LENGTH} from '../config/constants';
@@ -45,6 +46,7 @@ class IntentDetails extends Component {
             maxLength={INTENT_NAME_MAX_LENGTH}
             value={this.state.intent.intentName} />
         </div>
+        <AnswerSource />
         <h5 className="QuestionTitle">Question variants</h5>
         {
           this.state.intent.questions.map((question, index)=>{