* Revert "Revert "Migrate from ring to ed25519-dalek, take 2 (#3844)" (#3868)"
This reverts commit 6a878602f2a531e087d07fbf5cbeed02431567ca.
* Fix Signature::verify method
* Migrate from ring to ed25519-dalek
* Move gen_keypair_file test to a more appropriate location
* Fixup bench-exchange and add helper fn for single deterministic keypair
* Update golden