Ensure previous revisions are in benchmark tables
Ensure previous revisions are in benchmark tables

Address #550

The revision history at the top of the spec notebooks should include
all previous benchmarks. The Coffeescript now uses less than or equal
to when filtering the benchmarks.

usnistgov/chimad-phase-field,usnistgov/chimad-phase-field,wd15/chimad-phase-field,wd15/chimad-phase-field,usnistgov/chimad-phase-field,wd15/chimad-phase-field