Add :in to the list of values checked for booleans in inclusion_validator_for_checkbox?(val)
Add :in to the list of values checked for booleans in inclusion_validator_for_checkbox?(val)

The flag :within is no longer there for InclusionValidator for
booleans in latest Rails 4.2, and the function description for
validates_inclusion_of()[1] states that :within is an alias for :in,
so using that if it exists should ammount for the same.

[1]: https://github.com/rails/rails/blob/20c91119903f70eb19aed33fe78417789dbf070f/activemodel/lib/active_model/validations/inclusion.rb

activescaffold/active_scaffold,activescaffold/active_scaffold,activescaffold/active_scaffold