Update rake-compiler-dock to add 2.7 build

Author: pitr-ch

Gemfile

@@ -14,7 +14,7 @@ gem 'concurrent-ruby-ext', Concurrent::VERSION, options.merge(platform: :mri)
 group :development do
   gem 'rake', (Concurrent.ruby_version :<, 2, 2, 0) ? '~> 12.0' : '~> 13.0'
   gem 'rake-compiler', '~> 1.0', '>= 1.0.7'
-  gem 'rake-compiler-dock', '~> 0.7.0'
+  gem 'rake-compiler-dock', '~> 1.0'
   gem 'pry', '~> 0.11', platforms: :mri
 end