title: “.builders['browser']” should have required property 'class'
body: <p>After installing the dependencies successfully using npm install, I got the following error while running the server:</p>
  
  <pre><code>Schema validation failed with the following errors: Data path ".builders['browser']" should have required property 'class'.
  </code></pre>
  
  <p>After searching for a while, I think the problem is with <code>"@angular-builders/custom-webpack"</code>.</p>
  
  <p>The project was working good, but i accidentally deleted it and clone it again, then i got the error.</p>
  
  <p>Here's the dev dependencies:</p>
  
  <pre><code>"devDependencies": {
      "@angular-builders/custom-webpack": "latest",
      "@angular-builders/dev-server": "latest",
      "@angular-devkit/build-angular": "~0.13.6",
      "@angular/cli": "~7.3.6",
      "@angular/compiler-cli": "~7.2.10",
      "@angular/language-service": "~7.2.10",
      "@biesbjerg/ngx-translate-extract": "~2.3.4",
      "@types/jasmine": "~3.3.12",
      "@types/jasminewd2": "~2.0.3",
      "@types/node": "~11.11.4",
      "codelyzer": "~5.0.0-beta.1",
      "dotenv": "latest",
      "jasmine-core": "~3.3.0",
      "jasmine-spec-reporter": "~4.2.1",
      "karma": "~4.0.1",
      "karma-chrome-launcher": "~2.2.0",
      "karma-cli": "~2.0.0",
      "karma-coverage-istanbul-reporter": "~2.0.0",
      "karma-jasmine": "~2.0.1",
      "karma-jasmine-html-reporter": "~1.4.0",
      "protractor": "~5.4.2",
      "rxjs-tslint": "~0.1.7",
      "ts-node": "~8.0.3",
      "tslint": "~5.14.0",
      "typescript": "~3.2.0",
      "webpack": "~4.29.6"
  }
  </code></pre>
  
  <p>And here's my <strong>angular.json</strong> file:</p>
  
  <pre><code>{
      "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
      "version": 1,
      "newProjectRoot": "projects",
      "projects": {
          "iShop": {
              "root": "",
              "sourceRoot": "src",
              "projectType": "application",
              "prefix": "app",
              "schematics": {
                  "@schematics/angular:component": {
                      "styleext": "scss"
                  }
              },
              "architect": {
                  "build": {
                      "builder": "@angular-builders/custom-webpack:browser",
                      "options": {
                          "customWebpackConfig": {
                              "path": "extra-webpack.config.js"
                          },
                          "outputPath": "dist",
                          "index": "src/index.html",
                          "main": "src/main.ts",
                          "tsConfig": "src/tsconfig.app.json",
                          "polyfills": "src/polyfills.ts",
                          "assets": [
                              "src/favicon.ico",
                              "src/apple-touch-icon.png",
                              "src/robots.txt",
                              "src/manifest.json",
                              "src/assets"
                          ],
                          "styles": [
                              "src/main.scss",
                              "src/assets/css/paymentfont/paymentfont.min.css",
                              "./node_modules/font-awesome/css/font-awesome.css",
                              "./node_modules/@ng-select/ng-select/themes/default.theme.css"
                          ],
                          "scripts": []
                      }
                  },
                  "serve": {
                      "builder": "@angular-builders/dev-server:generic",
                      "options": {
                          "browserTarget": "iShop:build"
                      },
                      "configurations": {
                          "production": {
                              "browserTarget": "iShop:build:production"
                          }
                      }
                  }
              }
          },
          "iShop-e2e": {
              "root": "e2e",
              "projectType": "application",
              "architect": {
                  "e2e": {
                      "builder": "@angular-devkit/build-angular:protractor",
                      "options": {
                          "protractorConfig": "e2e/protractor.conf.js",
                          "devServerTarget": "iShop:serve"
                      }
                  },
                  "lint": {
                      "builder": "@angular-devkit/build-angular:tslint",
                      "options": {
                          "tsConfig": [
                              "e2e/tsconfig.e2e.json"
                          ],
                          "exclude": [
                              "**/node_modules/**"
                          ]
                      }
                  }
              }
          }
      },
      "defaultProject": "iShop"
  }
  </code></pre>
  
  <p>And my angular CLI version is: <strong>7.3.9</strong></p>