TST Test some basic storage of branched data
TST Test some basic storage of branched data

Add a test for BranchCollector and BranchedUniv
objects to ensure that we are storing the data
correctly. The test is fairly simple, and can only
requires changing two small routines for indexing
into underlying xs tables

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