convert uuid params to lower case, store only lower case uuids
fix false 'downloaded' status being returned when null hash is 'checked'
Lower case UUIDs - skins/avatars
high scalability!!! using '.' instead of 'null' string
Merge branch 'master' of github.com:Jake0oo0/crafatar
Revert "Lower case UUIDs - skins/avatars"
I already commited this ;)

This reverts commit e4bdecfbb756f38a85310a205a5693b7c5055f1b.
convert keys to lower case at cache level
clean up tests
- renamed a bunch of tests to be more descriptive
- added tests for lower/upper case uuid/name
- looping over the 4 IDs (see above) instead of redefining tests

fixes #40
I guess coveralls doesn't like the 'list' reporter
get rid of typo'd package description