Fixed wrong slash for Host

comsdk/communication.py

@@ -38,10 +38,13 @@ class Host(object):
                              'if you want to use it.')
         path_to_prog = self.programs[prog_name]
         if path_to_prog is not None:
-            return self.programs[prog_name] + '/' + prog_name
+            return self.join_path(self.programs[prog_name], prog_name)
         else:
             return prog_name
 
+    def join_path(self, *path_list):
+        return os.path.join(*path_list)
+
 
 class RemoteHost(Host):
     '''
@@ -75,6 +78,10 @@ class RemoteHost(Host):
         self.set_job_id = aux.load_function_from_module(state['job_setter'])
         self.check_task_finished = aux.load_function_from_module(state['job_finished_checker'])
 
+    def join_path(self, path_list):
+        # For RemoteHost, we assume that it is posix-based
+        return '/'.join(path_list)
+
 
 # Decorator
 def enable_sftp(func):