GridFTPFileTransferClient has file paths that refer to a local file paths need to generalize this

GridFTPFileTransferClient has file paths that refer to a local file paths need to generalize this

String username = "heshan";
String caFile = "/home/heshan/Dev/globusonline/transfer-api-client-java.git/trunk/ca/gd-bundle_ca.cert";
String certFile = "/tmp/x509up_u780936";
String keyFile = "/tmp/x509up_u780936";
String baseUrl = null;