This commit tweaks the debian packaging tool:
* All build environment metadata can now be overriden on the command
line. This allows testing the CI build behaviour locally.
* -unstable packages now actually contain the binaries (oops)
* packages use Go 1.7 to build
* archiving is skipped for PR builds
(cherry picked from commit 4f7627972e4997965be6f3c406904ef613e14c20)
9315bc9c3c