* Added delays between primary master starts and slave master starts
Merge pull request #42 from vsfs/fix_integration_test_on_travis

 * Added delays between primary master starts and slave master starts
 * Added FUSE library checking
 * Install fuse in travis
 + Added ServerMap::empty()
 + Added signature for VsfsRpcClient::mkdir()
 + Added RpcClientFactory
 + Added TestRpcClientFactory for test purpose
 * Move TestMockRpcClientFactory to rpc/mock_rpc_clients.h
 * Fixed the compiling issues for TestRpcClientFactory
* fixed part of code review.
* fixed unused parameter in index_manager_test
 + Added a simple test case for VsfsRpcClient::mkdir()
Merge pull request #43 from vsfs/fix_indexd_compile_warning

* fixed unused parameter in index_manager_test
 * Better comments on RpcClientFactory
 + Added back mkdir() to the VsfsClient interface class
 * Fixed virtual abstract function mkdir()
Merge pull request #44 from vsfs/client_mkdir

Add VsfsRpcClient::mkdir() and tons of test infrastructure.
 + rmdir() function code
 + Added a simple test case for VsfsRpcClient::rmdir
Merge branch 'master' of github.com:vsfs/vsfs into file_op