Fix a problem with empty yaml files

On some installations, YALM.load_file will give the error
Psych::SyntaxError:
control characters are not allowed at line 1 column 1
if the loaded file is entirely empty.
Merge pull request #1080 from jonas054/fix_psych_problem

Fix a problem with empty yaml files
[Fix #1022] Make auto-correct honor Exclude for individual cops
Merge pull request #1081 from jonas054/fix_1022_autocorrect_exclude

[Fix #1022] Make auto-correct honor Exclude for individual cops
Minor refactoring of SelfAssignment cop

unify offense message
tests should not use the same code its testing
Merge pull request #1082 from geniou/self_assignment_cleanup

Minor refactoring of SelfAssignment cop
Fix Exclude configuration not working on Windows

Check for an absolute in Windows style to avoid prefixing it with the
current directory.
Merge pull request #1076 from wndhydrnt/b-windows-exclude

Fix Exclude configuration not working on Windows
[Fix #1074] New cop SpaceBeforeComment
Merge pull request #1088 from jonas054/1074_space_before_comment

[Fix #1074] New cop SpaceBeforeComment
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