add preloader package and preloader itself to login page

package.json

@@ -10,6 +10,7 @@
     "picklock": "^0.5.1",
     "ramda": "^0.24.1",
     "react": "^15.6.0",
+    "react-bubble-preloader": "^1.3.2",
     "react-dom": "^15.6.0",
     "react-history": "^0.18.2",
     "react-modaliz": "^0.1.2",

src/modules/Preloader/Preloader.js

@@ -0,0 +1,15 @@
+import React from 'react';
+import BubblePreloader from 'react-bubble-preloader';
+
+import './Preloader.css';
+
+const Preloader = () => (
+    <BubblePreloader
+        bubble={{ width: '2rem', height: '2rem' }}
+        animation={{ speed: 2 }}
+        className="j-preloader"
+        colors={['#90c200', '#bde841', '#cee48f']}
+    />
+);
+
+export default Preloader;

src/modules/Preloader/Preloader.scss

@@ -0,0 +1,8 @@
+@import 'index.scss';
+
+.j-preloader {
+    position: absolute;
+    left: 50%;
+    top: 50%;
+    transform: translate(-50%, -50%);
+}

src/modules/pages/LoginPage/LoginForm.js

@@ -8,6 +8,7 @@ import Row from '../../Layout/Row/Row';
 import Button from '../../buttons/Button';
 import Logo from '../../Logo/Logo';
 import Icon from '../../Icon/Icon';
+import Preloader from '../../Preloader/Preloader';
 
 import './LoginForm.css';
 
@@ -21,7 +22,7 @@ const propTypes = {
 
 const LoginForm = ({ authorizeThroughGithub, errorMsg, isFetching }) => {
     if (isFetching) {
-        return <div>Loading... Ein Moment, bitte</div>;
+        return <Preloader />;
     }
 
     return (

yarn.lock

@@ -5192,6 +5192,10 @@ rc@^1.0.1, rc@^1.1.6, rc@^1.1.7:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
+react-bubble-preloader@^1.3.2:
+  version "1.3.2"
+  resolved "https://registry.yarnpkg.com/react-bubble-preloader/-/react-bubble-preloader-1.3.2.tgz#1416ccd88fe5e3eceba53cf1271b3b84713a7bc0"
+
 react-dev-utils@^3.0.0, react-dev-utils@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/react-dev-utils/-/react-dev-utils-3.0.2.tgz#1a42263e9b6aa11dcb45d69dfe5eb1b354bd5531"