title: Stripping non-alphanumeric chars but leaving spaces in Ruby
body: <p>Trying to change this:</p>
  
  <pre><code>"The basketball-player is great! (Kobe Bryant)"
  </code></pre>
  
  <p>into this:</p>
  
  <pre><code>"the basketball player is great kobe bryant"
  </code></pre>
  
  <p>Want to downcase and remove all punctuation but leave spaces...</p>
  
  <p>Tried <code>string.downcase.gsub(/[^a-z ]/, '')</code> but it removes the spaces</p>