Revert "Create tools/install_prereqs.sh"

This reverts commit 7be0b04

This work breaks the ability to do multi database installs,
revert until there is a working solution here, as this is going
to make fixing postgresql in tempest impossible.

Change-Id: I39a2b78542fe60233806d1005186ce1b31d4be17
diff --git a/stack.sh b/stack.sh
index 7306b58..9f734b9 100755
--- a/stack.sh
+++ b/stack.sh
@@ -648,7 +648,25 @@
 
 # Install package requirements
 echo_summary "Installing package prerequisites"
-$TOP_DIR/tools/install_prereqs.sh
+if is_ubuntu; then
+    install_package $(get_packages $FILES/apts)
+elif is_fedora; then
+    install_package $(get_packages $FILES/rpms)
+elif is_suse; then
+    install_package $(get_packages $FILES/rpms-suse)
+else
+    exit_distro_not_supported "list of packages"
+fi
+
+if [[ $SYSLOG != "False" ]]; then
+    if is_ubuntu || is_fedora; then
+        install_package rsyslog-relp
+    elif is_suse; then
+        install_package rsyslog-module-relp
+    else
+        exit_distro_not_supported "rsyslog-relp installation"
+    fi
+fi
 
 if is_service_enabled rabbit; then
     # Install rabbitmq-server