Fix error at anonymous keyword splat arguments

This fixes #1201.
Merge pull request #1206 from yujinakayama/fix-error-at-anonymous-keyword-splat-arg

Fix error at anonymous keyword splat arguments
Fix false positive in UnneededPercentQ for /%Q(something)/

Regular expressions starting with % or %Q were treated
as string literals starting with those delimiters.

Related to #835.
Merge pull request #1208 from jonas054/fix_unneeded_percent_q

Fix false positive in UnneededPercentQ for /%Q(something)/
[#835] New cop BarePercentLiterals

The style guide says:
Use %() (it's a shorthand for %Q) for single-line strings
which require both interpolation and embedded double-quotes.

This cop's job is to check that you use % rather than %Q,
or the opposite if so configured.
Merge pull request #1209 from jonas054/835_bare_percent_literal

[#835] New cop BarePercentLiterals