Fix login page

[knoxfighter]

I reworked the login-page to use bootstrap 4.

Also, i again updated the npm packages 😄

• @babel/core: 7.2.2 -> 7.4.5
• @babel/preset-env: 7.2.3 -> 7.4.5
• @fortawesome/fontawesome-free: 5.6.3 -> 5.8.2
• babel-loader: 8.0.5 -> 8.0.6
• bootstrap: 4.2.1 -> 4.3.1
• bootstrap-fileinput: 4.5.2 -> 5.0.3
• jquery: 3.3.1 -> 3.4.1
• mini-css-extract-plugin: 0.5.0 -> 0.7.0
• node-sass: 4.11.0 -> 4.12.0
• prop-types: 15.6.2 -> 15.7.2
• react: 16.7.0 -> 16.8.6
• react-dom: 16.7.0 -> 16.8.6
• react-native-listener: 1.0.2 -> 1.1.0
• react-router: 4.3.1 -> 5.0.0
• react-router-dom: 4.3.1 -> 5.0.0
• resolve-url-loader: 3.0.0 -> 3.1.0
• semver: 5.6.0 -> 6.1.1
• sweetalert2: 7.33.1 -> 8.11.6
• sweetalert2-react-content: 1.0.1 -> 1.1.0
• webpack: 4.28.4 -> 4.32
• webpack-cli: 3.2.1 -> 3.3.2
• webpack-fix-style-only-entries: 0.1.0 -> 0.2.0