title: OSError: [Errno 30] Read-only file system
body: <p>I am trying to run my flask app to lambda. It deploy successfully (using serverless framework) but when I'm testing I get this error :</p>
  <p><code>OSError: [Errno 30] Read-only file system</code></p>
  <p>Part of the code that trigger the error :</p>
  <pre><code>with open(&quot;tmp/some-file.zip&quot;, &quot;wb&quot;) as binary_file:
          binary_file.write(file_content)
  </code></pre>
  <p>Any suggestion ?</p>