.pell-button buttons should use type="button" attribute

[jmunozz]

When used in a form, simple button will trigger a submit.
You must add a type=button attribute to button.
Last version of Pell has fixed this issue.
I suggest to use last version of Pell.
UPDATE:
This issue should be solved by #21

[bar10]

Seems like this is still an open issue.