2.4.1

• Added type support through the type attribute, which just gets passed to
  reCaptcha. Possible values are 'audio' and 'image' (per reCaptcha docs).
  README was also update to show this attribute.

• Add required to opt out of validation

  Resolves #96 by adding and documenting the required attribute.
  When require is false or is a scoped variable which is false,
  the form validation will be removed.
  This is opt out to prevent a breaking change and usually the validation is
  preferred.

• Use recaptcha expired-callback instead of a hard-coded 2 min timeout

• Added documentation for changing the size