- Use explicit fakefs tag in specs

- Clean up trailing whitespace

spec/spec_helper.rb

@@ -76,10 +76,11 @@ end
 def normalize_space(s)
   s.gsub(/\n[\n\s]*/, "\n")
 end
-  
+
 RSpec.configure do |config|
+  config.treat_symbols_as_metadata_keys_with_true_values = true
   config.color_enabled = true
   config.order = 'rand'
-  config.include FakeFS::SpecHelpers
+  config.include FakeFS::SpecHelpers, :fakefs
   config.mock_with :rr
 end