Add new `Lint/SplatKeywordArguments` cop by koic · Pull Request #5871 · rubocop/rubocop

Summary This cop emulates the following Ruby warnings in Ruby 2.6. ruby/ruby@a23eca2 % ruby -we "def m(a) end; h = {foo: 1}; m(**h)" -e:1: warning: passing splat keyword arguments as a si...