Facilitate testing PRs from an external repo hosted on GH

Closes #129 (closed)

This will enable us to define the upstream and downstream repos along with their respective branches that need to be set as an external repo (i.e. hosted external to gitlab for eg. Github) for this project to function.

openstack-proxy/nodeimage.pkr.hcl

@@ -38,10 +38,8 @@ build {
 
   provisioner "shell" {
     inline = [
-      "sudo sed -i 's/^mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*",
-      "sudo sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*",
       "sudo yum install -y epel-release",
-      "sudo yum install -y libselinux-python3 python3 tmux vim git bash-completion curl wget unzip",
+      "sudo yum install -y libselinux-python3 python3 python3-pip tmux vim git bash-completion curl wget unzip",
       "sudo python3 -m pip install --upgrade pip",
       "sudo pip3 install s3cmd==2.3.0 ansible==4.10.0 python-openstackclient==5.8.0"
     ]