v0.6.71

Zygote v0.6.71

Diff since v0.6.70

Merged pull requests:

• Fix dead link (#1518) (@NAThompson)
• Prefer numeric zero over ZeroTangent for numeric arrays (#1524) (@BioTurboNick)
• Support enumerate in conditional generators/comprehensions (#1525) (@BioTurboNick)

Closed issues:

• "Zygote.Buffer copyto!" error when using "CartesianIndex" (#1364)
• Default presentation of gradients confusing? (#1519)
• BitVector failure (#1523)