Readme cat command does not work

[byoung]

Per the Readme, the command below does not work as cat is not in the PATH (not installed most likely)

docker run --rm -it mdsol/docker-ssh-exec cat /root/.ssh/id_rsa
Broadcasting UDP key request...
Got key from server.
Broadcasting UDP env request...
Recieved env from server
Setting 0 ENV vars from server: 
Writing key to /root/.ssh/id_rsa
Running command: cat /root/.ssh/id_rsa
ERROR starting command 'cat /root/.ssh/id_rsa': exec: "cat": executable file not found in $PATH
Deleting key file /root/.ssh/id_rsa...