[#549] network/Address: Add TLS

There is no TLS protocol support in
`go-multiaddr` library, but there is
public function that can register any
protocol that can be implemented outside
the library. Also `TLSEnabled` function
for parsing TLS protocol from
`network.Address` was added.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/network/tls_test.go

@@ -0,0 +1,48 @@
+package network
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAddress_TLSEnabled(t *testing.T) {
+	testCases := [...]struct {
+		input   string
+		wantTLS bool
+	}{
+		{"/dns4/localhost/tcp/8080", false},
+		{"/dns4/localhost/tcp/8080/tls", true},
+		{"/tls/dns4/localhost/tcp/8080", true},
+	}
+
+	for _, test := range testCases {
+		addr := Address{
+			ma: buildMultiaddr(test.input, t),
+		}
+
+		require.Equal(t, test.wantTLS, addr.TLSEnabled(), test.input)
+	}
+}
+
+func TestAddress_AddTLS(t *testing.T) {
+	input, tls := "/dns4/localhost/tcp/8080", tls.String()
+
+	testCases := [...]struct {
+		input string
+		want  string
+	}{
+		{input, input + tls},
+		{input + tls, input + tls},
+	}
+
+	for _, test := range testCases {
+		addr := Address{
+			ma: buildMultiaddr(test.input, t),
+		}
+
+		addr.AddTLS()
+
+		require.Equal(t, test.want, addr.String(), test.input)
+	}
+}