+ Added a class to set up a masterd cluster for test.
 * Extract the function of creating masterd cluster into
 TestMasterdCluster
 + Added missing files
 * Do not use C++ sleep_for for centos
 * Use TestMasterdCluster in client_metadata_test.cpp
 * TestMasterdCluster --> LocalMasterdCluster
 * FIXED: LocalMasterdCluster will create the base directory if not
 exists
 * Fixed typos