Puffing Billy - mkdir for cache path after configured

[eliotsykes]

rspec-rails-examples/spec/support/puffing_billy.rb

Lines 27 to 28 in 6f27836

	c.cache_path = "spec/support/http_cache/billy/"

Puffing Billy expects the developer to create the cache_path directory structure. If its not there it fails and logs an error to log/test.log. This error might be missed by a first-time user of puffing-billy.

Is there an option on Puffing Billy (latest version) to mkdir if it doesn't exist? Contribute?

If not, as part of puffing billy config, add a mkdir -p for the cache_path that runs immediately after its defined in spec/support/puffing_billy.rb.

[eliotsykes]

Consider renaming http_cache/billy -> http_cache/frontend (and vcr -> backend?)