Remove implicit reliance on sudo rights

[MitchellBerend]

Currently docker-mananger prefixes all docker commands with a sudo call to ensure the user has the rights to execute docker commands. This relies on the fact that the user that the ssh connection is made with, has sudo rights and these rights are configured to work without a password.

The end user should be able to choose if sudo is prepended to the docker command. This would ideally be done with a simple flag like -s/--sudo or maybe -b/--become like in ansible.