remove lib/debug.rb

lib/debug.gemspec

@@ -1,22 +0,0 @@
-Gem::Specification.new do |spec|
-  spec.name          = "debug"
-  spec.version       = "0.1.0"
-  spec.authors       = ["Yukihiro Matsumoto"]
-  spec.email         = ["matz@ruby-lang.org"]
-
-  spec.summary       = %q{Debugging functionality for Ruby}
-  spec.description   = %q{Debugging functionality for Ruby}
-  spec.homepage      = "https://github.com/ruby/debug"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
-  spec.licenses      = ["Ruby", "BSD-2-Clause"]
-
-  spec.metadata["homepage_uri"] = spec.homepage
-  spec.metadata["source_code_uri"] = spec.homepage
-
-  spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
-    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
-  end
-  spec.bindir        = "exe"
-  spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
-  spec.require_paths = ["lib"]
-end