Adding a .keys function to return the set of keys managed/stored by locache.
This will return an empty array if there are no keys currently stored.
Correcting a couple of mistakes in testing .keys functionality for sessionStorage and no storage.
Merge pull request #11 from bradhouse/master

Adding a .keys function to return the set of keys managed/stored by locache - Thanks @bradhouse!
Update README.rst
Update index.html
Release 0.4.0
Fixed failing tests which incorrectly assumed order.
Remove expireKey when no timeout is given
omitted the declaration of the expireKey
Added a test to check if a cached item is available after removing the timeout
Fixed a failing test and replicated it for session.js
Released 0.4.1 with minor bug fixes.
Merge branch 'master' into gh-pages