title: Handle unique email with Laravel using pqsql
body: <p>I've always used MySQL, however, I recently used pgsql for a new project. I noticed that with the default Laravel validation rules for registration, that a user could sign up with an email that has been used previously, as long as the case was different. 
  After looking into this, evidently, pgsql is a case-sensitive database. Therefore, test@email.com and Test@email.com are considered different. So the validation rule:</p>
  
  <pre><code>'email' =&gt; 'required|email|unique:users,email'
  </code></pre>
  
  <p>does not catch this case. I'm curious as to best practices for handling this. It could obviously be handled many different ways, just wondering how others deal with it.</p>