Lock ffi to fix test failures in the evented_file_update_checker_test

Author: rafaelfranca

Gemfile

@@ -15,6 +15,8 @@ gem 'coffee-rails', '~> 4.2'
 gem 'sass-rails'
 gem 'turbolinks', '~> 5'
 
+gem 'ffi', '1.9.10', require: false # FIXME: unlock ffi when https://github.com/nex3/rb-inotify/pull/49 is fixed.
+
 # require: false so bcrypt is loaded only when has_secure_password is used.
 # This is to avoid Active Model (and by extension the entire framework)
 # being dependent on a binary library.