title: babel@7 and jest configuration
body: <p>Maybe you may help me?
  I try to configure jest to use babel@7
  So I have:</p>
  
  <pre><code>"jest": "^23.4.1",
  "@babel/core": "^7.0.0-beta.54",
  "babel-7-jest": "^21.3.3",
  "babel-jest": "^20.0.3",
  </code></pre>
  
  <p>And jest config inside package.json</p>
  
  <pre><code>"jest": {
      "transform": {
        "^.+\\.js$": "babel-7-jest",
      },
  </code></pre>
  
  <p>And got </p>
  
  <pre><code>TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string
  </code></pre>
  
  <p>But if I use</p>
  
  <pre><code>"jest": {
      "transform": {
        "^.+\\.js$": "babel-jest",
      },
  </code></pre>
  
  <p>I got</p>
  
  <pre><code>Requires Babel "^7.0.0-0", but was loaded with "6.26.3". If you are sure you have a compatible version of @babel/core, it is likely that something in your build process is loading the wrong version. Inspect the stack trace of this error to look for the first entry that doesn't mention "@babel/core" or "babel-core" to see what is calling Babel.
  </code></pre>
  
  <p>babel config: <a href="https://gist.github.com/SilentImp/1506e9c26d16d9839a4469c6f3ae5c4d" rel="noreferrer">https://gist.github.com/SilentImp/1506e9c26d16d9839a4469c6f3ae5c4d</a></p>
  
  <p>Maybe you have some ideas?</p>