update Rails::Railtie::Configuration and ActionDispatch::Response#respond_to? to accept include_private argument
Merge pull request #15898 from arthurnn/backport_11912

Backport #11912 fix to 4-0-stable
inheritance_column need to be symbol to be removed from this hash

We put it with a symbol as name when building the default scope so we
have to use symbol to remove it.
Make dependencies.rb add a name to NameError
Merge pull request #15910 from yuki24/fix-name-error-name-bug-4-0

Backport of #15764 and #15902 to 4-0-stable
Remove travis hooks for notifications
README
Run only mysql2 test on travis
Rails config for raise on missing translations

Add a config to setup whether raise exception for missing translation or
not.

Conflicts:
	actionview/CHANGELOG.md
Reverse include_password defaults for dbconsole
Use HashWithIndifferentAccess for reflections

This prevents a bug where we try to access reflections with string
keys rather than symbols.