Improve resource handling

Gopkg.toml

@@ -1,6 +1,6 @@
 [[constraint]]
   name = "github.com/zondax/ledger-go"
-  version = "v0.7.0"
+  version = "v0.8.0"
 
 [prune]
   go-tests = true

common.go

@@ -17,8 +17,8 @@
 package ledger_cosmos_go
 
 import (
-	"fmt"
 	"encoding/binary"
+	"fmt"
 )
 
 type VersionInfo struct {

user_app.go

@@ -18,8 +18,9 @@ package ledger_cosmos_go
 
 import (
 	"fmt"
-	"github.com/zondax/ledger-go"
 	"math"
+
+	"github.com/zondax/ledger-go"
 )
 
 const (
@@ -40,11 +41,12 @@ const (
 	RequiredVersionPatch = 0
 )
 
-// User app
+// LedgerCosmos represents a connection to the Cosmos app in a Ledger Nano S device
 type LedgerCosmos struct {
 	api *ledger_go.Ledger
 }
 
+// FindLedgerCosmosUserApp finds a Cosmos app running in a device
 func FindLedgerCosmosUserApp() (*LedgerCosmos, error) {
 	ledgerApi, err := ledger_go.FindLedger()
 
@@ -61,12 +63,16 @@ func FindLedgerCosmosUserApp() (*LedgerCosmos, error) {
 	}
 
 	if appVersion.Major < RequiredVersionMajor {
-		return nil, fmt.Errorf("Version not supported")
+		return nil, fmt.Errorf("version not supported")
 	}
 
 	return &ledgerCosmosUserApp, err
 }
 
+func (ledger *LedgerCosmos) Close() error {
+	return ledger.api.Close()
+}
+
 func (ledger *LedgerCosmos) GetVersion() (*VersionInfo, error) {
 	message := []byte{userCLA, userINSGetVersion, 0, 0, 0}
 	response, err := ledger.api.Exchange(message)

validator_app.go

@@ -17,9 +17,10 @@
 package ledger_cosmos_go
 
 import (
-	"github.com/zondax/ledger-go"
 	"fmt"
 	"math"
+
+	"github.com/zondax/ledger-go"
 )
 
 const (