test: fix module name

Author: adamdecaf

examples/canonicalization_test.go

@@ -3,7 +3,7 @@ package examples
 import (
 	"testing"
 
-	"github.com/leifj/signedxml"
+	"github.com/moov-io/signedxml"
 
 	. "github.com/smartystreets/goconvey/convey"
 )

examples/examples_validate.go

@@ -5,7 +5,7 @@ import (
 	"io"
 	"os"
 
-	"github.com/leifj/signedxml"
+	"github.com/moov-io/signedxml"
 )
 
 func ExampleValidate() {

tests/issue55_test.go

@@ -5,7 +5,7 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/leifj/signedxml"
+	"github.com/moov-io/signedxml"
 
 	"github.com/stretchr/testify/require"
 )