wip caching api
ammend specs for caching on the api level
Add documentation.
Merge branch 'master' into cache-api

Conflicts:
	lib/viki/version.rb
Edit docs
Add the ability for viki base class to be assigned with a cacheable flag. Useful for caching non-holdbacks api endpoints.
Gotta cache 'em all. Cache endpoint client that's not subjected to holdbacks
Use setex to save cached object
Merge pull request #17 from viki-org/cache-api

Cache api for non-holdbacks endpoints