Bump version to be able to rely on associative indexing

[jjatria]

With the merge of #7, associative indexing is now supported, making the use of Cache::LRU much more convenient and transparent.

However, since the version hasn't been bumped since then, we cannot rely on this behavior, because we cannot require a version that supports this feature or check to see if the feature is available in the variant of 0.1.0 that a system has installed.

Could you bump Cache::LRU to a new version?