title: New GitHub actions run in empty folders
body: <p>I am working with new GitHub actions, idea of a workflow below is to run when pr is opened or synchronised, it should first check out and install dependencies and afterwards run few yarn scripts</p>
  
  <pre><code>name: PR to Master
  on: 
    pull_request:
      branches:
      - master
  jobs:
    # Synchronize or Opened
    synchronized_or_opened:
      name: Synchronize or Opened
      runs-on: ubuntu-latest
      steps:
      - uses: actions/bin/filter@master
        with:
          args: action 'opened|synchronize'
    # Add Labels
    add_labels:
      name: Add Labels
      runs-on: ubuntu-latest
      steps:
      - uses: actions/labeler@v2
        with:
          repo-token: ${{ secrets.GITHUB_TOKEN }}
      needs: synchronized_or_opened
    # Checkout
    checkout:
      name: Checkout
      runs-on: ubuntu-latest
      steps:
      - uses: actions/checkout@master
      needs: synchronized_or_opened
    # Install Dependencies
    install_dependencies:
      name: Install Dependencies
      runs-on: ubuntu-latest
      strategy:
        matrix:
          node-version: [10.x]
      steps:
      - run: yarn dep:install-npm
      needs: checkout
    # Typecheck
    typecheck:
      name: Typecheck
      runs-on: ubuntu-latest
      strategy:
        matrix:
          node-version: [10.x]
      steps:
      - run: yarn typecheck
      needs: install_dependencies
    # Prettier
    prettier:
      name: Prettier
      runs-on: ubuntu-latest
      strategy:
        matrix:
          node-version: [10.x]
      steps:
      - run: yarn prettier
      needs: install_dependencies
    # ESLint
    eslint:
      name: ESlint
      runs-on: ubuntu-latest
      strategy:
        matrix:
          node-version: [10.x]
      steps:
      - run: yarn eslint
      needs: install_dependencies
    # Danger
    danger:
      name: Danger
      runs-on: ubuntu-latest
      strategy:
        matrix:
          node-version: [10.x]
      steps:
      - run: yarn danger
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      needs: install_dependencies
  
  </code></pre>
  
  <p>At the moment it successfully gets to a checkout stage, but once Install job is ran I get following error</p>
  
  <blockquote>
    <p>error Couldn't find a package.json file in
    "/home/runner/work/myRepo/myRepo"</p>
  </blockquote>
  
  <p>Judging by this checkout either failed or I am in a wrong folder?</p>