Include latest and earliest record times in state (#34)

Reviewed-on: #34
Co-authored-by: Natercio Moniz <[email protected]>

internal/state.go

@@ -3,6 +3,7 @@ package internal
 import (
 	"context"
 	"encoding/json"
+	"time"
 
 	"github.com/shopspring/decimal"
 )
@@ -15,6 +16,8 @@ const StateVersion = "2"
 type State struct {
 	Version  string                       `json:"version"`
 	Platform string                       `json:"platform"`
+	Latest   time.Time                    `json:"latest"`
+	Earliest time.Time                    `json:"earliest"`
 	Queues   map[string][]persistedFiller `json:"queues"`
 }