Is your feature request related to a problem? Please describe.

ruby>=2.3 has squiggly heredoc (<<~) which does the same as Rails #strip_heredoc method.

Describe the solution you'd like

Would be good to have a cop that suggests/autofixes code that using <<-TEXT.strip_heredoc -> <<~TEXT.

Describe alternatives you've considered

/shrug

Additional context

x = <<~TEXT
  some text
    second line
TEXT

y = <<-TEXT.strip_heredoc
  some text
    second line
TEXT

p x == y # => true