Update rubocop requirement from ~> 0.63.0 to ~> 0.77.0 (#202)

Update rubocop requirement from ~> 0.63.0 to ~> 0.77.0

Co-authored-by: null <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: olbrich

ruby-units.gemspec

@@ -31,7 +31,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'pry'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec', '~> 3.0'
-  spec.add_development_dependency 'rubocop', '~> 0.63.0' # match codeclimate
+  spec.add_development_dependency 'rubocop', '~> 0.77.0' # match codeclimate
   spec.add_development_dependency 'simplecov-html'
   spec.add_development_dependency 'simplecov'
   spec.add_development_dependency 'terminal-notifier-guard'