centos7: don't install EPEL

EPEL is not really helping us test, because upstream RDO (and hence
centos openstack) are designed to run without it.  In fact it seems to
actively get in the way.

Installing EPEL here is really a hang-over from the snapshot days when
we'd boot provider images without it.  We do need EPEL for bringup but
should have it default disabled so we whitelist use; see depends-on
which moves it into dib.

Depends-On: I2d060e048f9106292f9024efe0fd1d529d801a30
Change-Id: If6cf1bc300c6b59a8defb09fb3a3a1254e392a43

install_puppet.sh

@@ -127,26 +127,13 @@ function setup_puppet_fedora {
 function setup_puppet_rhel7 {
     local puppet_pkg="https://yum.puppetlabs.com/puppetlabs-release-el-7.noarch.rpm"
 
-    # install a bootstrap epel repo to install latest epel-release
-    # package (which provides correct gpg keys, etc); then remove
-    # boostrap
-    cat > /etc/yum.repos.d/epel-bootstrap.repo <<EOF
-[epel-bootstrap]
-name=Bootstrap EPEL
-mirrorlist=https://mirrors.fedoraproject.org/mirrorlist?repo=epel-7&arch=\$basearch
-failovermethod=priority
-enabled=0
-gpgcheck=0
-EOF
-    yum --enablerepo=epel-bootstrap -y install epel-release
-    rm -f /etc/yum.repos.d/epel-bootstrap.repo
-
     _systemd_update
     yum update -y
 
     # NOTE: we preinstall lsb_release to ensure facter sets lsbdistcodename
     yum install -y redhat-lsb-core git
 
+    # Install puppetlabs repo & then puppet comes from there
     rpm -ivh $puppet_pkg
     yum install -y puppet
 
@@ -156,7 +143,7 @@ EOF
     sed -i '/templatedir/d' /etc/puppet/puppet.conf
 
     # install RDO repo as well; this covers a few things like
-    # openvswitch that aren't available for EPEL
+    # openvswitch that aren't available
     yum install -y https://rdoproject.org/repos/rdo-release.rpm
 }