Add staypuft-client-installer

Existing staypuft-installer now generates answer file for client
installer. Client installer prepares puppet on target machine and
registers itself in staypuft.

Generates SSH Key for foreman-proxy user and configures the
foreman-proxy service to use puppetssh

It creates foreman .ssh directory and copies the private ssh key
from the foreman-proxy user. This allows DynFlow tasks running as
foreman user to ssh into host machines, allow tasks to test that ssh is
fully configured.
no-daemonize puppetssh commmand

Service puppet stop kills any running puppet agent daemon.  This is
causing any --onetime puppetssh runs to fail mid run when trying to stop
the agent service.  Running in non daemon modes prevents this.
Remove get_ready implementation from ProvisioningWizard

The base class implementation does the same thing. There is no need to
override in the subclass. The subclass implementation has unknown
constants and does not work.
Fix a syntax error
Pass settings as string when using Foreman > 1.6
Make the RPM installable on RHEL 7
Rename param to staypuft_ssh_public_key for consistency

(for consistency with already existing ssh_public_key)
Set staypuft_ssh_public_key as a host parameter

and still keep it set in a smart class parameter in case some host group
includes the foreman::plugin::staypuft_client class.

The problem with previous approach was that if the host was
provisioned without foreman::plugin::staypuft_client puppet class
assigned to it, setting of the authorized key for puppetssh would fail
and the host would be "bricked" until either reprovisioned or set the
authorized key manually.
Remove puppetmaster param from staypuft_client.pp

The param is not used there, and it is not set in the answerfile,
which made it generate a default of local host's fqdn, which was
confusing and incorrect.
Wait for client registration to finish

Add "--no-daemonize" to registration puppet run so that we wait for it
to finish.

Add "-l console" so that it actually writes the output to
foreman-installer log as intended (instead of system journal).
Fail the installer if the registration puppet run fails
Wait for certificate to allow manual signing
Workaround for http://projects.theforeman.org/issues/7975
Remove EPEL repo from RHEL

It shouldn't be required for RHEL, the RPMs should come from
subscriptions there.
Merge pull request #106 from jistr/puppetssh

Puppetssh