Some tests assert that a specific commit subject does or doesn't occur
in the main view; interactive_rebase/outside_rebase_range_select.go is
an example for this, it asserts `t.Views().Main().Content(
DoesNotContain("commit 06"))`. The problem with this kind of assertion
and our test commit naming scheme is that the diff view begins with a
"commit <hash>" line, and when that hash happens to start with "06" the
assertion matched it and failed spuriously. This was usually masked by
our MaxAttempts=2 that we currently use for integration tests (it's
quite unlikely that the commit gets a hash beginning with "06" twice in
a row). However, we want to get to a state where we can set MaxAttempts
to 1, so make this more robust by changing our naming scheme.
It starts a rebase on the bottom-most commit of the range, and sets all the
selected commits to "edit" (skipping merge commits, because they can't be
edited).
