Current Foreman 1.8 nightly, with foreman-installer-staypuft, running on CentOS 6.6 server has these yum repos enabled in "Kickstart Default" provisioning template for openstack deployments:

repo --name="Extra Packages for Enterprise Linux" --mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-<%= @host.operatingsystem.major >&arch=<= @host.architecture >
repo --name=foreman-nightly --baseurl=http://yum.theforeman.org/plugins/nightly/el<= @host.operatingsystem.major >/<= @host.architecture %>

So only the "foreman plugins" repo is added. Unfortunately that repo is not enough to install foreman-installer-staypuft-client rpm on a provisioned CentOS 7 host, see the yum error below.
Basicly foreman-installer-staypuft-client depends on foreman-installer, which is in the main repo, not in the plugins repo. So either the dependencies of the foreman-installer-staypuft-client needs to be fixed, or also the foreman nightly repo is needed for el7 hosts, like this:

repo --name="Extra Packages for Enterprise Linux" --mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-<%= @host.operatingsystem.major >&arch=<= @host.architecture >
repo --name=foreman-nightly --baseurl=http://yum.theforeman.org/nightly/el<= @host.operatingsystem.major >/<= @host.architecture >
repo --name=foreman-plugins-nightly --baseurl=http://yum.theforeman.org/plugins/nightly/el<= @host.operatingsystem.major >/<= @host.architecture %>

Yum error on el7 host (with only the plugins repo added):

Resolving Dependencies
--> Running transaction check
---> Package foreman-installer-staypuft-client.noarch 1:0.5.3-1.el7 will be installed
--> Processing Dependency: rubygem-kafo >= 0.6.0 for package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch
--> Processing Dependency: foreman-installer >= 1.5.0 for package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch
--> Processing Dependency: ruby(release) for package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch
--> Running transaction check
---> Package foreman-installer-staypuft-client.noarch 1:0.5.3-1.el7 will be installed
--> Processing Dependency: rubygem-kafo >= 0.6.0 for package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch
--> Processing Dependency: foreman-installer >= 1.5.0 for package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch
---> Package ruby-libs.x86_64 0:2.0.0.353-22.el7_0 will be installed
--> Finished Dependency Resolution
Error: Package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch (foreman-plugins)
Requires: foreman-installer >= 1.5.0
Error: Package: 1:foreman-installer-staypuft-client-0.5.3-1.el7.noarch (foreman-plugins)
Requires: rubygem-kafo >= 0.6.0
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest