add machine dockerfile

machine.Dockerfile

+FROM archlinux:latest
+
+RUN pacman-key --init
+RUN pacman -Sy
+
+RUN cat <<EOF >> /etc/pacman.conf
+
+[mypkgs]
+SigLevel = Optional TrustAll
+Server = http://localhost/mypkgs
+EOF
+
+CMD /bin/bash