ng test throws Error: Cannot find module '@angular-cli/plugins/karma'

I am trying to get started with testing in my project. I saw many posts that said I needed to update my karma.conf.js file from angular-cli/plugins/karma to @angular-cli/plugins/karma. Anywhere where I am referencing angular-cli I put the @ symbol in front of it. This has not fixed my error.

What am I missing?

Here is the error:

06 06 2017 11:04:09.268:ERROR [config]: Error in config file!
 { Error: Cannot find module '@angular-cli/plugins/karma'
    at Function.Module._resolveFilename (module.js:470:15)
    at Function.Module._load (module.js:418:25)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at module.exports (/.../karma.conf.js:12:7)
    at Object.parseConfig (.../node_modules/karma/lib/config.js:410:5)
    at new Server (.../node_modules/karma/lib/server.js:56:20)
    at Promise (.../node_modules/@angular/cli/tasks/test.js:34:33)
    at Class.run (.../node_modules/@angular/cli/tasks/test.js:15:16)
    at Class.run (.../node_modules/@angular/cli/commands/test.js:101:25)
    at Class.Command.validateAndRun (.../node_modules/@angular/cli/ember-cli/lib/models/command.js:128:15)
    at .../node_modules/@angular/cli/ember-cli/lib/cli/cli.js:92:22
    at tryCatch (.../node_modules/rsvp/dist/lib/rsvp/-internal.js:216:12)
    at invokeCallback (.../node_modules/rsvp/dist/lib/rsvp/-internal.js:231:13)
    at .../node_modules/rsvp/dist/lib/rsvp/then.js:29:16
    at flush (.../node_modules/rsvp/dist/lib/rsvp/asap.js:85:5) code: 'MODULE_NOT_FOUND' }

Here is my config file

// Karma configuration file, see link for more information
// https://karma-runner.github.io/0.13/config/configuration-file.html

module.exports = function (config) {
  config.set({
    basePath: '',
    frameworks: ['jasmine', '@angular-cli'],
    plugins: [
      require('karma-jasmine'),
      require('karma-chrome-launcher'),
      require('karma-remap-istanbul'),
      require('@angular-cli/plugins/karma'),
      require('karma-htmlfile-reporter')
    ],
    files: [
      { pattern: './src/test.ts', watched: false }
    ],
    preprocessors: {
      './src/test.ts': ['@angular-cli']
    },
    remapIstanbulReporter: {
      reports: {
        html: 'coverage',
        lcovonly: './coverage/coverage.lcov'
      }
    },
    angularCli: {
      config: './angular-cli.json',
      environment: 'dev'
    },
    mime: {
      'text/x-typescript': ['ts','tsx']
    },
    reporters: ['progress', 'karma-remap-istanbul', 'html'],
    htmlReporter: {
      outputFile: 'tests/units.html',

      // Optional
      pageTitle: 'Unit Tests for Frontend',
      subPageTitle: 'Should always be passing.',
      groupSuites: true,
      useCompactStyle: true,
      useLegacyStyle: true
    },
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['Chrome'],
    singleRun: false
  });
};