Improved the build matrix.
Merge pull request #19 from thedrow/patch-2

Improved the build matrix.
Minor clarification to readme

Add import line to first settings example.
Merge pull request #20 from meshy/patch-5

Minor clarification to readme
URL schema standardized

Uses standard url schema for sockets, querystring to allow for cache
arguments and an optional redis database url component.

Related to ghickman/django-cache-url#16 and ghickman/django-cache-url#14
Update redis url format to match convention.

The database number is specified in the path to match how other DSN's specify
database names.
Rewrote structure and format of tests

Grouped each cache into a single test case.
More explicit testing of different aspects.