title: Ramda: find object key by nested key value
body: <p>Is there any function in ramda how can I find key by nested key value? I found a way how to find an object in array but that doesn't help. I need something like this:</p>
  
  <pre class="lang-js prettyprint-override"><code>const obj = {
    addCompany: {
      mutationId: '1'
    },
    addUser: {
      mutationId: '2'
    },
    addCompany: {
      mutationId: '3'
    }
  }
  const findByMutationId = R.???
  findByMutationId('2', obj) // returns addUser
  </code></pre>