add failing test for two replication groups
make time values more explicit
add failing test for multiple clusters in one replica

cleanup test stubs and remove ordering dependencies
return timestamp of youngest cache cluster for a replica group

in order to know which cache cluster is the most current one
make tests ruby 1.8.x compatible again
update README
Revert "make tests ruby 1.8.x compatible again"

This reverts commit 7022485305449b8e8badcc2914a6d2219c99b5f6.
guarantee ruby 1.8.x compatibility

use trailing dots instead of escaping the newlines
Merge pull request #20 from Jimdo/enable_finer_elasticache_distinction

Enable finer elasticache distinction