Prefer Dir over Rake::FileList

This also fixes all the CI inconsistencies.

Fixes: titusfortner#184

Signed-off-by: Utkarsh Gupta <utkarsh@debian.org>

webdrivers.gemspec

@@ -3,7 +3,6 @@
 lib = File.expand_path('lib', __dir__)
 $LOAD_PATH.unshift lib unless $LOAD_PATH.include?(lib)
 require 'webdrivers/version'
-require 'rake/file_list'
 
 Gem::Specification.new do |s|
   s.name        = 'webdrivers'
@@ -23,8 +22,7 @@ Gem::Specification.new do |s|
     'source_code_uri' => "https://github.com/titusfortner/webdrivers/tree/v#{Webdrivers::VERSION}"
   }
 
-  s.files         = Rake::FileList['CHANGELOG.md', 'lib/**/*', 'LICENSE.txt', \
-                                   'README.md'].exclude(*File.read('.gitignore').split)
+  s.files         = Dir['lib/**/*'] + %w[CHANGELOG.md LICENSE.txt README.md]
   s.test_files    = Dir['spec/**/*'].reject { |f| File.directory?(f) }
   s.executables   = []
   s.require_paths = ['lib']