Automorphism group certificates for cubic vertex-transitive graphs

A collection of certificates witnessing that a graph has the specified group as its full automorphism group. The certificates are given for the 111674 graphs from the combined censuses of connected cubic vertex-transitive graphs on up to 1280 vertices by Potočnik, Spiga and Verret, and of connected cubic symmetric graphs on up to 2048 vertices by Conder. See README.md below for more details. The current version differs by the original version by a bugfix in autgrp_cert.sage and corrected certificated for graphs with IDs 420 (in autgrp_cert_1_100.json.gz), 680, 756, 1687, 2082 (in autgrp_cert_101_200.json.gz) and all 17 certificates in autgrp_cert_hard_cases.json.gz. The correctness of the certificates has been verified by a Lean program written by Luka Opravš.