add a deb package for pass/secret service backends

Note that this single source package produces two binary packages: one for
-pass, and one for -secretservice, so that users can install whichever
password backend (and thus deps) that they want.

Signed-off-by: Tycho Andersen <tycho@docker.com>

deb/debian/control

@@ -0,0 +1,25 @@
+Source: docker-credential-helpers
+Section: admin
+Priority: optional
+Maintainer: Docker <support@docker.com>
+Homepage: https://dockerproject.org
+Standards-Version: 3.9.6
+Vcs-Browser: https://github.com/docker/docker-credential-helpers
+Vcs-Git: git://github.com/docker/docker-credential-helpers.git
+Build-Depends: debhelper
+  , dh-make
+  , libsecret-1-dev
+
+Package: docker-credential-secretservice
+Architecture: any
+Depends: libsecret-1-0
+  , ${misc:Depends}
+Description: docker-credential-secretservice is a credential helper backend
+ which uses libsecret to keep Docker credentials safe.
+
+Package: docker-credential-pass
+Architecture: any
+Depends: pass
+  , ${misc:Depends}
+Description: docker-credential-secretservice is a credential helper backend
+ which uses the pass utility to keep Docker credentials safe.