Cleanup gemspec

tapping_device.gemspec

@@ -15,15 +15,13 @@ Gem::Specification.new do |spec|
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = "https://github.com/st0012/tapping_device"
-  spec.metadata["changelog_uri"] = "https://github.com/st0012/tapping_device/releases"
+  spec.metadata["changelog_uri"] = "https://github.com/st0012/tapping_device/CHANGELOG.md"
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added into git.
   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"]
 
   spec.add_dependency "method_source", "~> 1.0.0"