title: Rails number_field_tag won't accept a float even with :step
body: <p>I have a number of entry fields laid out in a table, and one of the entries is:</p>
  
  <pre><code>&lt;td&gt;&lt;%= number_field_tag :elasticity, :step =&gt; 0.1 %&gt;&lt;/td&gt;
  </code></pre>
  
  <p>When I enter a non-integer value such as 1.3 and try to post the form, it pops up with "Please enter a valid value. The two nearest valid values are 1 and 2". The up and down arrows increment by 1, too, not 0.1.</p>
  
  <p>The HTML that is being produced is:</p>
  
  <pre><code>&lt;td&gt;&lt;input id="elasticity" name="elasticity" type="number" value="{:step=&amp;gt;0.1}" /&gt;&lt;/td&gt;
  </code></pre>
  
  <p>So I can't see why it's not accepting non-integer values. Can anybody suggest what I've done wrong?</p>