Swallow bundler exceptions when running tests

Let's avoid useless output when testing stuff related to Bundler.
:scissors:
Remove duplicated HashWithIndifferentAccess#with_indifferent_access.
[ci skip] Fix Compiler's Github link
implement ActiveRecord::Base#pretty_print + changelog
[ci skip] add created_at and updated_at to example
document generators hidden_namespaces
Test `except!` in other cases too
[ci skip] Correct output of Hash#symbolize_keys
Merge pull request #15448 from akshay-vishnoi/doc_changes

[ci skip] Correct output of Hash#symbolize_keys
Fix AS::NumberHelper results with rationals

:precision was incorrectly being applied to Rationals

before:
  ActiveSupport::NumberHelper.number_to_rounded Rational(10, 3), precision: 2
  => "3.3"
after:
  ActiveSupport::NumberHelper.number_to_rounded Rational(10, 3), precision: 2
  => "3.33"
[ci skip] correct doc for ActionView::Helpers::DebugHelper
Missing period from AP/CHANGELOG [ci skip]
Merge pull request #15449 from aditya-kapoor/correct-debug-doc

[ci skip] correct doc for ActionView::Helpers::DebugHelper
Removed 'Caching with Rails' guide from WIP, this guide isn't ready to
be published and requires more attention. [ci skip]
config.assets.digests -> config.assets.digest

in Asset Pipeline guide.

[skip ci]
Merge pull request #15456 from jonatack/patch-7

config.assets.digests -> config.assets.digest
Merge branch 'master' of github.com:rails/docrails
Create Changing Columns on migrations guides

[ci skip]
Add Total of grouped items to AR query interface on guides

[ci skip]