Added Build skeleton

Dockerfile

@@ -0,0 +1,16 @@
+FROM docker:8
+LABEL maintainer="Torben Nehmer <torben@nehmer.net>"
+
+RUN set -ex; \
+	apt-get update; \
+	\
+	apt-get install -y --no-install-recommends \
+		ssmtp \
+	; \
+	\
+	rm -rf /var/lib/apt/lists/* ;\
+	apt-get clean ;\
+
+# Finally, publish the rootfs file into the container
+# This is done as last step to make docker build caching more efficient.
+ADD rootfs.tar.gz /