title: Cypress causing type errors in jest assertions
body: <p>I had been using <code>react-testing-library</code> as well as <code>@testing-library/jest-dom/extend-expect</code>. I installed Cypress yesterday, and now I'm getting Typescript errors on all my jest matchers:</p>
  
  <p><code>Property 'toEqual' doesn't exist on type 'Assertion'. Did you mean 'equal'?</code></p>
  
  <p>It looks like it's getting the type of <code>expect</code> from the wrong assertion library or something? Also, <code>expect(...).to.equal(...)</code> doesn't even work either.</p>
  
  <p>I actually tried installing <code>@types/jest</code> and yarn appears to have succeeded but it's not listed in my <code>package.json</code>'s <code>devDependencies</code>. </p>
  
  <p>Here's my <code>tsconfig</code></p>
  
  <pre><code>{
    "compilerOptions": {
      "target": "es5",
      "lib": [
        "dom",
        "dom.iterable",
        "esnext"
      ],
      "allowJs": true,
      "skipLibCheck": true,
      "esModuleInterop": true,
      "allowSyntheticDefaultImports": true,
      "strict": true,
      "noImplicitAny": false,
      "forceConsistentCasingInFileNames": true,
      "module": "esnext",
      "moduleResolution": "node",
      "resolveJsonModule": true,
      "isolatedModules": false,
      "noEmit": true,
      "jsx": "react",
      "skipDefaultLibCheck": true,
      "types": [
        "node",
        "cypress",
        "jest"
      ]
    },
    "include": [
      "src"
    ]
  }
  </code></pre>
  
  <p>I'll also mention that all my <code>cy</code> calls in my cypress tests are getting a <code>cy is not defined</code> error from ESLint.</p>