ensure scp destination directories exist (with mkdir -p)

in SSH launchers.

As described in  #3411

closes  #3411

IPython/parallel/apps/launcher.py

@@ -600,6 +600,11 b' class SSHLauncher(LocalProcessLauncher):'
                 time.sleep(1)
             else:
                 break
+        remote_dir = os.path.dirname(remote)
+        self.log.info("ensuring remote %s:%s/ exists", self.location, remote_dir)
+        check_output(self.ssh_cmd + self.ssh_args + \
+            [self.location, 'mkdir', '-p', '--', remote_dir]
+        )
         self.log.info("sending %s to %s", local, remote)
         check_output(self.scp_cmd + [local, remote])
     
@@ -623,6 +628,9 b' class SSHLauncher(LocalProcessLauncher):'
                 time.sleep(1)
             elif check == u'yes':
                 break
+        local_dir = os.path.dirname(local)
+        if not os.path.exists(local_dir):
+            os.makedirs(local_dir)
         check_output(self.scp_cmd + [full_remote, local])
     
     def fetch_files(self):