Improve the reproducible build process.

* Moved stuff into it's own `reproducible-builds` directory.
* Improved reproducible build by using a debian snapshot and more clearly listing dependencies.
* Removed signing from assembleReelase.
* Updated README.

reproducible-builds/docker/print-versions.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+while read dep; do
+  dep_name=$(echo $dep | cut -f1 -d '=')
+  version=$(dpkg -s $dep_name | grep 'Version: ' | cut -f2 -d ' ')
+  echo "$dep_name=$version"
+done < $1