pump.io: 1.0.0 -> 3.0.0

The package stopped building for some unknown reason (npm could no
longer fetch a module).

This is one of the build failures listed in #23253.

    http://hydra.nixos.org/build/49551309
    http://hydra.nixos.org/build/49548753

Easiest fix is to upgrade to latest stable version and regenerate
packages with node2nix.

The databank-memcached dependency needed to be dropped due to
dependency failures.