Use new pattern style

Avoid a depreciation warning:

Warning: Deprecated pattern style '.../vendor/**' in .../config/default.yml. Change to '.../vendor/**/*'."
Merge pull request #1091 from Dorian/patch-1

Use new pattern style
Cleanup specs

* use described_class
* do not use instance variables
* do not start example description with should
[Fixes #1094] Fix bug in ClassAndModuleChildren

ClassAndModuleChildren incorrectly flaged class with a single method
Merge pull request #1095 from geniou/rspec_cleanup

Cleanup specs
Merge pull request #1096 from geniou/class_and_module_children_single_method

[Fixes #1094] Fix bug in ClassAndModuleChildren
Fix incorrect error message about rubocop-todo.yml
Merge pull request #1098 from agrimm/todo_filename

Fix incorrect error message about rubocop-todo.yml
Add -F/--fail-fast option

Inspect files in order of modification time, newest first. And stop after the first file with offenses.
Merge pull request #1089 from jonas054/fail_fast

Add -F/--fail-fast option
Cut 0.22.0
[Fix #1104] Fix EachWithObject with modifier if
Merge pull request #1105 from geniou/each_with_object_fix

Fix EachWithObject with modifier if
Add optional require directive to .rubocop.yml
Merge pull request #1102 from geniou/config_require

Add optional require directive to .rubocop.yml
[Fix #1097] Add namespace for cop names in configuration

LineLength becomes Style/LineLength etc.
Merge pull request #1103 from jonas054/namespaces_in_config

Namespaces for cop names
Remove unnecessary hash merge in TargetFinder

The typo fail_level instead of fail_fast didn't affect function, so
that whole thing is unnecessary. Let values default to nil instead of
false. Works the same.
[Fix #1106] EachWithObject with method call body
Merge pull request #1108 from geniou/each_with_object_fix

[Fix #1106] EachWithObject with method call body