Comply with current umask when generating new app:

When creating a new application using the default rails generator
(`rails new my_app`), it will apply some permissions bypassing the
current process umask. The `bin' directory and any files inside it will
always be set a mode of 0755.

  This change removes the current umask bits from the mode applied by
the generator on the `bin' directory and its content.

railties/lib/rails/generators/rails/app/app_generator.rb

@@ -68,7 +68,7 @@ module Rails
       directory "bin" do |content|
         "#{shebang}\n" + content
       end
-      chmod "bin", 0755, verbose: false
+      chmod "bin", 0755 & ~File.umask, verbose: false
     end
 
     def config