function mailTo(email, text, options) {
  if (typeof text === 'object') {
    options = text;
    text = null;
  }
  options = options || {};
  options.href = encodeURI('mailto:' + email);
  
  return tag('a', options, function() {
    return escape(text || email);
  });
}
Construct a mailto: link tag.

Examples:

  mailTo('johndoe@example.com');
  // => "<a href="mailto:johndoe@example.com">johndoe@example.com</a>"

  mailTo('johndoe@example.com', 'John Doe');
  // => "<a href="mailto:johndoe@example.com">John Doe</a>"

  mailTo('johndoe@example.com', 'John Doe', { class: 'email' });
  // => "<a class="email" href="mailto:johndoe@example.com">John Doe</a>"

@param {String} email
@param {String} text
@param {Object} options
@return {String}
@api public