title: Jinja2 '-' in variable, bug?
body: <p>I am making my first steps at flask, I'm trying to make custom html tags with wtf-forms</p>
  
  <p>when i use this:</p>
  
  <pre><code>{{form.email(data-trigger="hover")}}
  </code></pre>
  
  <p>i got this: </p>
  
  <pre><code>jinja2.exceptions.TemplateSyntaxError: expected token ',', got '='
  </code></pre>
  
  <p>without it everything works:</p>
  
  <pre><code>{{form.email(datatrigger="hover")}}
  </code></pre>
  
  <p>is there any way to fix it?</p>