Boolean hidden field uses name when :nested

Closes #619
Merge pull request #620 from carnesmedia/boolean_field_ignores_input_html

Boolean hidden field uses name when :nested
Update CHANGELOG
allow to add additional classes only for wrapper

closes #629
Merge pull request #630 from nashby/fix-issue-629

allow to add additional classes only for wrapper
Cache the `additional_classes` method to not compute the classes in
every call
Update CHANGELOG
Fix double quote typo
Merge pull request #645 from jayshepherd/master

Fix double quote that should have been a single quote in the README
Welcome to the team, @nashby! :sparkles:

[ci skip]
fix typo
Merge pull request #653 from Agis-/patch-1

fix typo
add ability to specify checked and uncked values for boolean input

closes #643
update CHANGELOG

[ci skip]
Merge pull request #651 from nashby/fix-issue-643

add ability to specify checked and uncked values for boolean input
refactor disabled_test

separate expectations to own test cases
use assert_no_select instead of css selector
refactor general_test

separate expectations to own test cases
use assert_no_select instead of css selector
refactor readonly_test

separate expectations to own test cases
use assert_no_select instead of css selector
add config for wrapper mappings.

This should be a hash containing an input type as key and the wrapper
that will be used for all inputs with specified type

config.wrapper_mapings = { :string => :string_wrapper }
update CHANGELOG