add travis autobuild scripts (courtesy of EmuTOS project)

.travis/register_apt_repositories.sh

@@ -0,0 +1,19 @@
+#!/bin/bash -eu
+# -e: Exit immediately if a command exits with a non-zero status.
+# -u: Treat unset variables as an error when substituting.
+
+if [ $UID != 0 ]
+then
+  echo "error: This script needs to be run with root access rights." 2>&1
+  exit 1
+fi
+
+# Display expanded script commands
+set -x
+
+# Vincent Rivière's m68k-atari-mint cross-tools
+# http://vincent.riviere.free.fr/soft/m68k-atari-mint/ubuntu.php
+sudo add-apt-repository -y ppa:vriviere/ppa
+
+# Update the packages list
+apt-get update -qq