Timeout when pulling SEEK Publication API

[whomingbird]

Describe the bug:
When HITS website wants to synchronize publications using seek api, it receives occasional timeout errors.
The result is that some publications are not fetched..

Suspect reason:
Server limits ?

Possible solution:
Provide API with time span filter:
It is now possible to only retrieve a list of publications that have been updated in the past 24 hours instead of all publications (https://publications.h-its.org/publications.json).