* add dynamic options for cache * fixed bugs based on unit-test * add doc for cache * make cache implements be private * Change simpleCache name to InMemoryCache Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com> * Remove fake cache and replacing to in memory cache with default parameter Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com> Signed-off-by: Wenhao Zhou <wenhaozhou@yunify.com>