Travis: Revert to basic-min for Tor 0.3.5
In legacy/trac#33379 (moved), we changed CI to use single-onion-v23 for 0.3.5, because some other chutney networks were unstable.
Once legacy/trac#33428 (moved) or legacy/trac#33583 (moved) are fixed, we should be able to revert to basic-min.