BUG Properly set burnup, days for multiple universes, no burnup
BUG Properly set burnup, days for multiple universes, no burnup

Closes GH Issue #345 by setting the days and burnup value to
zero if no burnup data found in the resdata dictionary. This
assumes that burnup data is always present in the file before
we hit the group constant section, which is valid for the versions
of Serpent we support.

CORE-GATECH-GROUP/serpent-tools,CORE-GATECH-GROUP/serpent-tools