Bug#898610: Should stop running tests during build as they are for `autopkgtest`

[Emmanuel Bourg]

I don't think we should stop running the unit tests during the build,
that would prevent us from catching obvious regressions or
incompatibilities before the package is uploaded.

The real question I think is what do we want to run as part of the
autopkgtests? Do we run the unit tests again? The integration tests for
the Maven projects having them?

I also wonder if the autopkgtests should rebuild the project to run the
tests, or rely on a prebuilt test binary installed alongside the main
artifact (but this may significantly increase the size of the binary
package in some cases).