input_action_*(class = "foo") doesn't work

[cpsievert]

>>> from shiny import *
>>> input_action_button(class = "foo")
  File "<stdin>", line 1
    input_action_button(class = "foo")
                        ^
SyntaxError: invalid syntax

[wch]

It needs to be class_, right?

[cpsievert]

Ack, sorry, wrong error message (#47 fixes it)

>>> input_action_button("foo", "bar", class_ = "foo")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/cpsievert/github/prism/shiny/input_action_button.py", line 13, in input_action_button
    return tags.button(
TypeError: button() got multiple values for keyword argument 'class_'

[wch]

Ah, that makes sense. This is the same issue as posit-dev/py-htmltools#10. I think it would make sense to modify htmltools so that it's easier to pass along kwargs without worrying about name conflicts, because this will be a pretty common problem.