Apparently our DBD::SQLite links against /usr/lib/libsqlite3.dylib,
which is an old version that doesn't respect foreign key constraints.
So manifests/cache.sqlite doesn't get updated properly when a manifest
disappears. We should fix our DBD::SQLite, but in the meantime this
will fix the test.
http://hydra.nixos.org/build/3017959
* `nix-install-package --help' (NIX-9).
* `nix-install-package --non-interactive': don't prompt or pause.
* Tests for nix-install-package.
* Security fixes: filter the values obtained from the nixpkg.
* Removed some dead code (successor stuff) from nix-push.
* Updated terminology in the tests (store expr -> drv path).
* Check that the deriver is set properly in the tests.