publish results for dict_keys([None]) branches

[amcnicho]

Results from testing certain wheels are not rendered properly in the generated HTML. The git commands that map date to revision (asv/commands/publish.py) are

1. git rev-list -n 1 {tag}
2. git rev-list --all --date-order --reverse

In certain cases this mapping fails to identify the proper coordinate for a given result datum. Possibly limited to revisions that reference edits directly on master, although that would still include builds for release branches when there have been issues generating a build via automated CI systems (e.g., all the wheels from release/6.1.1).

Undesirable output of `asv publish`

[ 33.33%] ·· Couldn't find 511c796525183a955f5c2383b7b866ddc755b20c in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 1794fbb276a6a332c30974d7fe1b893853b456e4 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find e605fc21706005b4c5dbf80cfb83da74e37a4ccb in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 02a5c5522c96f533bea65a496edf69bd9434ff25 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find e40d0b393fec6bfdb9c119a121db74dabc37d374 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 6c88b054b8a867a9f76b33b328b62e45d6872e86 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 853e1e5526138739b5e34361dc7fc50aadc1b614 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 709a4c90d723c8a1d7921a5d635af40e06d7e4fb in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find a73a44ba2df3c3b824e866ed60bf0d538e532f76 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 02e613c19b2daa1569dcd6d94448b6c4f75f3cb3 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 6f36161c410d06d2b9824ac4aed3e245c0fbca19 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 6734dfe0361a77e06bd27199636bb91491b555dd in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 6ff8d2788d0dded9fa87f13908d761fd8e0cf481 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 4f5295c7309e931c62f928a03eeadbbb4984cf00 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 3442b967dbbb51c44d51335dbb69ba11ffa3f5e8 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find aa3603a192281900ba4f590d81f6d8e31b3409d6 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find a7741e6bba97affc341733873c445905ec124ccd in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find dddbc346f5840f46d095b9a6bc39476b76758b7a in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 353eb19ddcc63a021798112cf86b766374a8306a in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 572d1107c77f919eaea263d964782a8cfe6e82f3 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 2302e3bdd186c6ab939acef47f56557f2043847d in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 883cbf256fba2db0c9f4f35ba936d7628de257e4 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find aa58aa9b3aa20de055592cecfc07ba657cf51733 in dict_keys([None]) branches
[ 33.33%] ·· Couldn't find 02a5c5522c96f533bea65a496edf69bd9434ff25 in dict_keys([None]) branches