Revert "try out rubocop lint and autocorrect"

This reverts commit 5272c827404aa599b70d59bdf0bdf03aedf55e41.
add rubocop to Gemfile

This reverts commit b78efeb8d5eaa56ee4896525707d2b9b673ba7c7.
add rubocop config
add auto generated rubocop_todo
rubocop: autocorrect Style/TrailingWhitespace
rubocop: autocorrect Style/TrailingBlankLines
rubocop: autocorrect Style/SpaceAfterComma
rubocop: autocorrect Style/SpaceAroundOperators
rubocop: disable Style/BracesAroundHashParameters
rubocop: autocorrect Style/EmptyLines
rubocop: autocorrect Style/SingleSpaceBeforeFirstArg
rubocop: autocorrect Style/SpaceBeforeBlockBraces
rubocop: autocorrect Style/SpaceBeforeComma
rubocop: autocorrect Style/SpaceInsideBlockBraces
rubocop: autocorrect Lint/StringConversionInInterpolation [???]
rubocop: autocorrect Lint/UnusedBlockArgument
rubocop: autocorrect Style/AlignHash
rubocop: autocorrect Style/AlignParameters
rubocop: fix Style/AndOr
rubocop: disable Style/Blocks [???]