Add wtogami to gitian download scripts.
Made the build/release process completable verbatim as listed in
release-process.md
Make the rand tests determinstic. (fixes #2714)

This avoids spurious errors with the old tests but still tests
 enough that if the rng is replaced with a totally broken one
 it should still fail.
Merge pull request #2796 from gmaxwell/remove_overactive_rand_tests

Make the rand tests determinstic.
Merge pull request #2816 from wtogami/gitianwtogami

Add wtogami to gitian download scripts.
Merge pull request #2817 from Michagogo/release-process-followable-verbatim

Made the build/release process completable verbatim as listed in release-process.md