installation: jellyfish update to 0.3.1

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
utils: arXiv identifier normalization

* Adds support for normalizing arxiv identifiers according
  to http://arxiv.org/help/arxiv_identifier and
  http://arxiv.org/help/arxiv_identifier_for_services.

* Fixes issues with pre-2007 arxiv identifier validation.

* Fixes PEP257 problems.

* Adds tests including missing assertion of to_url() method.

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