Update go dependencies

vendor/github.com/spf13/afero/copyOnWriteFs_test.go

@@ -21,3 +21,19 @@ func TestCopyOnWrite(t *testing.T) {
 	}
 
 }
+
+func TestCopyOnWriteFileInMemMapBase(t *testing.T) {
+	base := &MemMapFs{}
+	layer := &MemMapFs{}
+
+	if err := WriteFile(base, "base.txt", []byte("base"), 0755); err != nil {
+		t.Fatalf("Failed to write file: %s", err)
+	}
+
+	ufs := NewCopyOnWriteFs(base, layer)
+
+	_, err := ufs.Stat("base.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+}