[ruby/io-wait] Fixed regexp to reject .travis* at the toplevel only

https://github.com/ruby/io-wait/commit/4434b10e46

ext/io/wait/io-wait.gemspec

@@ -15,7 +15,7 @@ Gem::Specification.new do |spec|
 
   spec.files         = Dir.chdir(File.expand_path('..', __FILE__)) do
     `git ls-files -z`.split("\x0").reject do |f|
-      f.match(%r{\A(?:test|spec|features)/|\A\.git|\.travis})
+      f.match(%r{\A(?:test|spec|features)/|\A\.(?:git|travis)})
     end
   end
   spec.bindir        = "exe"