Run both the golang tests and make sure the exporter can start.

From debhelper 14 it'll be called automatically

Fix some issues reported by lintian

See merge request !2

Changes-By: lintian-brush
Fixes: lintian: package-uses-old-debhelper-compat-version
See-also: https://lintian.debian.org/tags/package-uses-old-debhelper-compat-version.html

Fix some issues reported by lintian

See merge request !1

Changes-By: lintian-brush
Fixes: lintian: missing-built-using-field-for-golang-package
See-also: https://lintian.debian.org/tags/missing-built-using-field-for-golang-package.html

Changes-By: lintian-brush
Fixes: lintian: uses-debhelper-compat-file
See-also: https://lintian.debian.org/tags/uses-debhelper-compat-file.html

Changes-By: lintian-brush
Fixes: lintian: package-uses-deprecated-debhelper-compat-version
See-also: https://lintian.debian.org/tags/package-uses-deprecated-debhelper-compat-version.html

Changes-By: lintian-brush
Fixes: lintian: build-depends-on-obsolete-package
See-also: https://lintian.debian.org/tags/build-depends-on-obsolete-package.html

Changes-By: lintian-brush
Fixes: lintian: insecure-copyright-format-uri
See-also: https://lintian.debian.org/tags/insecure-copyright-format-uri.html

Use the system's value for HZ (100 by default), which is the unit that
cgroups cpuacct statistics are using.

Actually register the right prometheus Handler. Also make the server
wait for a metrics collection cycle to complete before starting the
HTTP server, so we never serve missing metrics.