Go back to using mainine velocity

We moved off to our own fork of velocity many moons ago to fix
a memory leak bug when velocity was being barely maintained. They
have now merged the bugfix, so go back to mainline.

src/Velociraptor.js

@@ -1,7 +1,7 @@
 const React = require('react');
 const ReactDom = require('react-dom');
 import PropTypes from 'prop-types';
-const Velocity = require('velocity-vector');
+const Velocity = require('velocity-animate');
 
 /**
  * The Velociraptor contains components and animates transitions with velocity.

src/VelocityBounce.js

@@ -1,4 +1,4 @@
-const Velocity = require('velocity-vector');
+const Velocity = require('velocity-animate');
 
 // courtesy of https://github.com/julianshapiro/velocity/issues/283
 // We only use easeOutBounce (easeInBounce is just sort of nonsensical)

src/components/structures/BottomLeftMenu.js

@@ -19,8 +19,8 @@ import React from 'react';
 import ReactDOM from 'react-dom';
 import sdk from '../../index';
 import dis from '../../dispatcher';
-import Velocity from 'velocity-vector';
-import 'velocity-vector/velocity.ui';
+import Velocity from 'velocity-animate';
+import 'velocity-animate/velocity.ui';
 import SettingsStore from '../../settings/SettingsStore';
 
 const CALLOUT_ANIM_DURATION = 1000;

src/components/views/dialogs/DeactivateAccountDialog.js

@@ -21,7 +21,7 @@ import sdk from '../../../index';
 import Analytics from '../../../Analytics';
 import MatrixClientPeg from '../../../MatrixClientPeg';
 import * as Lifecycle from '../../../Lifecycle';
-import Velocity from 'velocity-vector';
+import Velocity from 'velocity-animate';
 import { _t } from '../../../languageHandler';
 
 export default class DeactivateAccountDialog extends React.Component {