allow resource expansions to be cached (fix greedy non-caching conditional)

this intention of this conditional was to bypass the cache for collection 
resources, but had an additional consequence of not caching resource 
expansions when you are asking for a resource
Merge pull request #74 from stormpath/cache-fixes

allow resource expansions to be cached (fix greedy non-caching condition...
update changelog, package.json
Merge pull request #75 from stormpath/release-0.4.3

Release 0.4.3