Review changes and operator -> coordinator

common/coordinator.go

@@ -0,0 +1,18 @@
+package common
+
+import (
+	eth "github.com/ethereum/go-ethereum/common"
+)
+
+// Coordinator represents a Hermez network coordinator who wins an auction for an specific slot
+// WARNING: this is strongly based on the previous implementation, once the new spec is done, this may change a lot.
+type Coordinator struct {
+	CoordinatorID CoordinatorID
+	Forger        eth.Address // address of the forger
+	Beneficiary   eth.Address // address of the beneficiary
+	Withdraw      eth.Address // address of the withdraw
+	URL           string      // URL of the coordinators API
+}
+
+// CoordinatorID is use to identify a Hermez coordinator
+type CoordinatorID uint64