Add ed25519, tests will fail until ed25519 verification fix

ledger_common.go

@@ -0,0 +1,19 @@
+package crypto
+
+import (
+	ledger "github.com/zondax/ledger-goclient"
+)
+
+var device *ledger.Ledger
+
+// Ledger derivation path
+type DerivationPath = []uint32
+
+// getLedger gets a copy of the device, and caches it
+func getLedger() (*ledger.Ledger, error) {
+	var err error
+	if device == nil {
+		device, err = ledger.FindLedger()
+	}
+	return device, err
+}