title: Laravel 5.4 - Correct Validation rule for a required parameter that can be zero
body: <p>I'm trying to validate a request to load stock into a table. Up until now stock has always had a positive value and the following validation rule worked exactly as expected:</p>
  
  <pre><code>[
      "value" =&gt; "required|integer|min:0"
  ]
  </code></pre>
  
  <p>Stock is stored and can have multiple values and <em>now</em> stock can have a <code>value</code> of zero (0), I don't think it works with the 'required' rule.</p>
  
  <p>I have changed it to use 'present' which I thought should suffice however it still fails, and adding 'nullable' also doesn't work:</p>
  
  <pre><code>[
      "value" =&gt; "present|integer|min:0"
  ]
  </code></pre>
  
  <p>Are there validation rules to specify that a field must be present but the value can be zero?</p>