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/create_team/components/display_name.jsx

@@ -8,6 +8,8 @@ import {cleanUpUrlable} from 'utils/url.jsx';
 
 import logoImage from 'images/logo.png';
 
+import PropTypes from 'prop-types';
+
 import React from 'react';
 import ReactDOM from 'react-dom';
 import {FormattedMessage} from 'react-intl';
@@ -124,6 +126,6 @@ export default class TeamSignupDisplayNamePage extends React.Component {
 }
 
 TeamSignupDisplayNamePage.propTypes = {
-    state: React.PropTypes.object,
-    updateParent: React.PropTypes.func
+    state: PropTypes.object,
+    updateParent: PropTypes.func
 };

webapp/components/create_team/components/team_url.jsx

@@ -8,6 +8,8 @@ import * as URL from 'utils/url.jsx';
 
 import logoImage from 'images/logo.png';
 
+import PropTypes from 'prop-types';
+
 import React from 'react';
 import ReactDOM from 'react-dom';
 import {Button, Tooltip, OverlayTrigger} from 'react-bootstrap';
@@ -242,6 +244,6 @@ export default class TeamUrl extends React.Component {
 }
 
 TeamUrl.propTypes = {
-    state: React.PropTypes.object,
-    updateParent: React.PropTypes.func
+    state: PropTypes.object,
+    updateParent: PropTypes.func
 };

webapp/components/create_team/create_team_controller.jsx

@@ -8,6 +8,8 @@ import TeamStore from 'stores/team_store.jsx';
 import {FormattedMessage} from 'react-intl';
 import {browserHistory, Link} from 'react-router/es6';
 
+import PropTypes from 'prop-types';
+
 import React from 'react';
 
 export default class CreateTeamController extends React.Component {
@@ -90,5 +92,5 @@ export default class CreateTeamController extends React.Component {
 }
 
 CreateTeamController.propTypes = {
-    children: React.PropTypes.node
+    children: PropTypes.node
 };