Cleanup released gem

alba.gemspec

@@ -20,11 +20,7 @@ Gem::Specification.new do |spec|
     'rubygems_mfa_required' => 'true'
   }
 
-  # 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(__dir__)) do
-    `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
-  end
+  spec.files = Dir["lib/**/*", "CHANGELOG.md", "LICENSE.txt", "README.md"]
   spec.bindir        = 'exe'
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']