grants: initial release

* Adds new module for harvesting and maintaining list of grants.
  (closes #62)

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
installation: requirements update

* Updates Python packages to their latest versions.

* Documents Zenodo's management of requirements.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>