title: Pytest doesnt find file out of the test folder
body: <p>I'm trying to create a test at pytest using moto to upload a Cloud Formation to AWS using boto3.</p>
  <p>The test I'm doing is this one:</p>
  <pre><code>def test_main_success(self, cf):
      'Test upload with a new stack'
      sys.stdout = mystdout = io.StringIO()
      expected_return = (
                      &quot;Criando teste\n&quot;
                      &quot;...aguardando resposta da aws...\n&quot;
                      &quot;Sucesso\n&quot;
                      )
  
      main([&quot;teste&quot;, &quot;teste.yaml&quot;])
      content = mystdout.getvalue()
      assert content == expected_return
  </code></pre>
  <p>The problem is that it doesn't find the file.</p>
  <pre><code>FileNotFoundError: [Errno 2] No such file or directory: './resources/teste.yaml'
  </code></pre>
  <p>But the file is there and when I try the script it runs just fine, and gets the file.</p>
  <p>The file where it's trying to get is in the folder of the script not the folder of the test</p>
  <pre><code>├── cl_uploader
  │   ├── cl_uploader.py
  │   ├── __init__.py
  │   └── resources
  │       ├── 1-ec2-with-sg-eip.yaml
  │       └── teste.yaml
  └── tests
      ├── resources
      │   └── teste.yaml
      └── test_cl_uploader.py
  </code></pre>
  <p>The pytest don't get files out of the folder where the test is?</p>