update gemspec with include files

testzed.gemspec

@@ -13,8 +13,6 @@ Gem::Specification.new do |spec|
   spec.homepage = "https://github.com/thoughtbot/testzed"
   spec.required_ruby_version = ">= 3.0.0"
 
-  spec.metadata["allowed_push_host"] = "TODO: Set to your gem server 'https://example.com'"
-
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = "https://github.com/thoughtbot/testzed"
   spec.metadata["changelog_uri"] = "https://github.com/thoughtbot/testzed/blob/main/CHANGELOG.md"
@@ -25,7 +23,7 @@ Gem::Specification.new do |spec|
   spec.files = IO.popen(%w[git ls-files -z], chdir: __dir__, err: IO::NULL) do |ls|
     ls.readlines("\x0", chomp: true).reject do |f|
       (f == gemspec) ||
-        f.start_with?(*%w[bin/ test/ spec/ features/ .git .github appveyor Gemfile])
+        f.start_with?(*%w[bin/ lib/ test/ .git .github Gemfile])
     end
   end
   spec.bindir = "exe"