Add release-deb & release-rpm scripts.

These will create the apt & yum repos for the deb/rpms generated by build-deb
and build-rpm.

Adds sign-repo script which signs the repo metadata with a gpg key.

Signed-off-by: Jessica Frazelle <princess@docker.com>
Upstream-commit: c850e97c84abffc71509692ab1accd38408fa51b
Component: engine

components/engine/Dockerfile

@@ -37,6 +37,7 @@ RUN apt-get update && apt-get install -y \
 	bash-completion \
 	btrfs-tools \
 	build-essential \
+	createrepo \
 	curl \
 	dpkg-sig \
 	git \