add rubocop to dev dependencies and add a default todo
add rubocop to default rake test

This should make travis care about it
RUBOCOP: Favor modifier while usage when you have a single-line body.

For some reason this one doesn’t end up disabled in the TODO file, so
just fixing right away so things pass for now.
RUBOCOP AlignArray

lib/lolcommits/plugins/lol_twitter.rb:31:16: C: [Corrected] Align the
elements of an array literal if they span more than one line.
               Twitter::Error::BadRequest,
               ^^^^^^^^^^^^^^^^^^^^^^^^^^
lib/lolcommits/plugins/lol_twitter.rb:32:16: C: [Corrected] Align the
elements of an array literal if they span more than one line.
               Twitter::Error::ClientError => e
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^
RUBOCOP AlignParameters

AUTOCORRECTED: Align the parameters of a method call if they span more
than one line.
RUBOCOP EmptyLines

AUTOCORRECTED: Extra blank line detected.
RUBOCOP TrailingBlankLines, TrailingComma, TrailingWhitespace

[Corrected] 1 trailing blank lines detected.
[Corrected] Trailing whitespace detected.
[Manually Fixed] Avoid comma after the last item of a hash.
RUBOCOP SpaceAroundOperators

autocorrected
RUBOCOP Blocks

[Corrected] Avoid using {...} for multi-line blocks.
RUBOCOP CollectionMethods

[Corrected] Prefer reduce over inject.