Updating client dependencies. Switching to yarn. (#6433)

* Updating client dependancies. Switching to using yarn.

* Updating React

* Moving pure components to using function syntax (performance gains with newer react version)

* Updating client dependancies.

* Ignore .yarninstall

* Enabling pre-lockfile because it's the entire point of using yarn.

* Removing old webpack config

* Moving to new prop-types

* Fixing ESLint Errors

* Updating jest snapshots.

* Cleaning up package.json

webapp/components/analytics/statistic_count.jsx

@@ -3,33 +3,33 @@
 
 import {FormattedMessage} from 'react-intl';
 
+import PropTypes from 'prop-types';
+
 import React from 'react';
 
-export default class StatisticCount extends React.Component {
-    render() {
-        const loading = (
-            <FormattedMessage
-                id='analytics.chart.loading'
-                defaultMessage='Loading...'
-            />
-        );
+export default function StatisticCount(props) {
+    const loading = (
+        <FormattedMessage
+            id='analytics.chart.loading'
+            defaultMessage='Loading...'
+        />
+    );
 
-        return (
-            <div className='col-md-3 col-sm-6'>
-                <div className='total-count'>
-                    <div className='title'>
-                        {this.props.title}
-                        <i className={'fa ' + this.props.icon}/>
-                    </div>
-                    <div className='content'>{this.props.count == null ? loading : this.props.count}</div>
+    return (
+        <div className='col-md-3 col-sm-6'>
+            <div className='total-count'>
+                <div className='title'>
+                    {props.title}
+                    <i className={'fa ' + props.icon}/>
                 </div>
+                <div className='content'>{props.count == null ? loading : props.count}</div>
             </div>
-        );
-    }
+        </div>
+    );
 }
 
 StatisticCount.propTypes = {
-    title: React.PropTypes.node.isRequired,
-    icon: React.PropTypes.string.isRequired,
-    count: React.PropTypes.number
+    title: PropTypes.node.isRequired,
+    icon: PropTypes.string.isRequired,
+    count: PropTypes.number
 };