Produce RPM packages

Reference from https://github.com/dotnet/core-setup/tree/master/src/pkg/packaging/rpm

The goal is to have parity with Debian,
but does not publish to the feed

When run the script with rhel, it will
produce rpm file in the package step
and publish rpm to the blob storage

scripts/obtain/uninstall/dotnet-uninstall-rpm-packages.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) .NET Foundation and contributors. All rights reserved.
+# Licensed under the MIT license. See LICENSE file in the project root for full license information.
+#
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+current_userid=$(id -u)
+if [ $current_userid -ne 0 ]; then
+    echo "$(basename "$0") uninstallation script requires superuser privileges to run"
+    exit 1
+fi
+
+host_package_name="dotnet-host"
+
+remove_all(){
+    yum remove -y $host_package_name
+}
+
+is_dotnet_host_installed(){
+    local out="$(yum list installed | grep $host_package_name)"
+    [ -z "$out" ]
+}
+
+is_dotnet_host_installed
+[ "$?" -eq 0 ] && echo "Unable to find dotnet installation to remove." >&2 \
+    && exit 0
+
+remove_all
+[ "$?" -ne 0 ] && echo "Failed to remove dotnet packages." >&2 && exit 1
+
+is_dotnet_host_installed
+[ "$?" -ne 0 ] && \
+    echo "dotnet package removal succeeded but appear to still be installed. Please file an issue at https://github.com/dotnet/cli" >&2 && \
+    exit 1
+
+echo "dotnet package removal succeeded." >&2
+exit 0