pump.io: init at git-2015-11-09

pump.io -- Social server with an ActivityStreams API

The version from git master branch is used because released version 0.3
is not compatible with newer versions of nodejs.

node-packages.json was extracted from pump.io package.json and augmented
with the databank-{lrucache,memcached,mongodb,redis} driver packages.

To regenerate, run:
    npm2nix pkgs/servers/web-apps/pump.io/node-packages.json pkgs/servers/web-apps/pump.io/node-packages.nix