New rule: Avoid single-line methods.

SingleLineMethods reports methods implemented on a single line. It has
a configuration option called AllowIfMethodIsEmpty, which is true by
default.
Merge pull request #109 from jonas054/one_line_methods

New rule: Avoid single-line methods.
New cop FavorJoin
New cop BlockComments
added ability to ignore directories
Merge pull request #110 from bolandrm/exclude_directories

Added ability to ignore directories
Renamed Indentation cop to CaseIndentation
Minor improvements to the changelog markup
Fixed BraceAfterPercent
fixed BraceAfterPercent spec for Ruby < 2.0
Merge pull request #112 from jurriaan/brace_after_percent_fix

Fixed BraceAfterPercent
Renamed EmptyLines cop to EmptyLineBetweenDefs
Add a check for missing .rubocop.yml
New cop EmptyLines