Pushing-Images-to-Azure: Update to include RHEL 7.6 within scope

None of the content is inherently Fedora 29, and so these changes indicate
that the RHEL 7.6 release is within scope. In addition, changing the yum
repos entry to use the "yum-config-manager --add-repo=" operation as it is
somewhat less subject to typos.

_posts/2018-10-08-Pushing-Images-to-Azure.md

@@ -14,9 +14,8 @@ include the necessary agents, as well as
 
 ## Prerequisites
 
-We'll use [Fedora 29](https://getfedora.org/) as our OS of choice for running this. Run
-this in its own VM with at least 8 gigabytes of memory and 40 gigabytes of disk space.
-[Lorax](http://weldr.io/lorax/) makes some changes to the operating system its running on.
+Run this in its own VM with at least 8 gigabytes of memory and 40 gigabytes of disk space.
+[Lorax](https://weldr.io/lorax/) makes some changes to the operating system its running on.
 
 First install Composer:
 
@@ -41,7 +40,7 @@ If you're going to use [Cockpit](https://cockpit-project.org/) UI to drive Compo
 Install the [Azure CLI](https://docs.microsoft.com/en-us/cli/azure/install-azure-cli-yum) tooling:
 
     $ sudo rpm --import https://packages.microsoft.com/keys/microsoft.asc
-    $ sudo sh -c 'echo -e "[azure-cli]\nname=Azure CLI\nbaseurl=https://packages.microsoft.com/yumrepos/azure-cli\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc" > /etc/yum.repos.d/azure-cli.repo'
+    $ sudo yum-config-manager --add-repo=https://packages.microsoft.com/yumrepos/azure-cli
     $ sudo yum install azure-cli
 
 Now log into the Azure CLI like so: