benchbuild.db.versions.001_Remove_RegressionTest_table module

Remove unneeded Regressions table.

This table can and should be reintroduced by an experiment that requires it.

benchbuild.db.versions.001_Remove_RegressionTest_table.downgrade(migrate_engine)

benchbuild.db.versions.001_Remove_RegressionTest_table.upgrade(migrate_engine)