Moved ssh_command to base class and pylint love.

* Moved ssh_command to CLI base as having it under helpers was
  importing Base, which was not very elegant. If UI guys need to run
  ssh command, they'll have to deal with instantiating Base.
* Calmed pylint down.
Merge pull request #204 from omaciel/ssh_command

Moved ssh_command to base class and pylint love.