Added a default INTERVAL constant. This represents the amount of time which the class takes in seconds. EG hour = 3600, day - 86400
Added another case statement which will give the cache an expiry time if the cache responds to :expire. NOTE: Only redis does this for now.
Renamed INTERVAL to DEFAULT_TTL
TTL means time to live. Interval is ambigious and non descript
Added debugger and redis for testing certain functions in the middleware
Added tests for a default_ttl method which should always return and Fixnum. This is so it can be used to determine the maximum amount of time a key should likve
Added another test to check the expiry specific functions of redis
Added default_ttl method and removed the constant.
Updated the call to hourly and daily to use a class method to fetch default_ttl
Added a new test to check that the cache has an associated expiry time when a hit is detected
Updated defatul_ttl to be a class method
Fixed bug where the expirey was not being hit when  the cache responded to :expire.
This was becuase I was using cases (only one is executed followed by a break). Embarassingly simple mistake