title: Jest's test match does not pick my test files
body: <p>Hey I can't get <code>testMatch</code> to pick up my test file. Here's my config:</p>
  
  <pre><code>module.exports = {
      preset: 'jest-puppeteer',
      testMatch: [
          '**/tests/**/?(*.)+spec.js'
      ]
  };
  </code></pre>
  
  <p>My directory layout:</p>
  
  <pre><code>- Automation
      -  jest.config.js
      - tests
          - single-property
              - index.spec.js
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>No tests found, exiting with code 1
  Run with `--passWithNoTests` to exit with code 0
  In C:\Users\&lt;user_name&gt;\WebstormProjects\Automation
    4 files checked.
    testMatch: **/tests/**/?(*.)+spec.js - 0 matches
    testPathIgnorePatterns: \\node_modules\\ - 4 matches
    testRegex:  - 0 matches
  Pattern:  - 0 matches
  </code></pre>