Added logic for get-buckets callback
Added logic for get-buckets callback

braydonf/libstorj,Storj/libstorj-c,aleitner/libstorj-c,braydonf/libstorj-c,braydonf/libstorj,Storj/libstorj-c,aleitner/libstorj-c,braydonf/libstorj-c