Updated to rubocop 0.26.0
Rubocop: DeprecatedClassMethods
Rubocop: CommentIndentation
Rubocop: Adapt tests to deprecated method fixes
Rubocop: AlignParameters
Rubocop: Disable SingleSpaceBeforeFirstArg permanent
Rubocop: EmptyLinesAroundAccessModifier
Rubocop: EmptyLinesAroundBody
Rubocop: IndentHash
Rubocop: LeadingCommentSpace
Rubocop: NegatedIf
Rubocop: NumericLiterals
Rubocop: PercentLiteralDelimiters
Rubocop: SpaceBeforeComma
Rubocop: SpaceInsideParens
Rubocop: SpaceInsideBrackets
Rubocop: WordArray
Bugfix: destination dir was ignored during install
Bugfix: wrong variable for default used
Rubocop: Moved several rules to permanent, fixed UselessAssignment