Add ssh client to dockerfile
Add ssh client to dockerfile

vyulabs/semaphore,laeshiny/semaphore,rastaman/semaphore,vyulabs/semaphore,youhong316/semaphore,laeshiny/semaphore,laeshiny/semaphore,youhong316/semaphore,rastaman/semaphore,vyulabs/semaphore,ansible-semaphore/semaphore,ansible-semaphore/semaphore,ansible-semaphore/semaphore,rastaman/semaphore,youhong316/semaphore,vyulabs/semaphore,ansible-semaphore/semaphore,youhong316/semaphore,laeshiny/semaphore,rastaman/semaphore