Maintenance: split each provider in a package

- Fix VyprVPN port
- Fix missing Auth overrides

internal/provider/utils/pick_test.go

@@ -0,0 +1,26 @@
+package utils
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_PickRandomConnection(t *testing.T) {
+	t.Parallel()
+	connections := []models.OpenVPNConnection{
+		{Port: 1}, {Port: 2}, {Port: 3}, {Port: 4},
+	}
+	source := rand.NewSource(0)
+
+	connection := PickRandomConnection(connections, source)
+	assert.Equal(t, models.OpenVPNConnection{Port: 3}, connection)
+
+	connection = PickRandomConnection(connections, source)
+	assert.Equal(t, models.OpenVPNConnection{Port: 3}, connection)
+
+	connection = PickRandomConnection(connections, source)
+	assert.Equal(t, models.OpenVPNConnection{Port: 2}, connection)
+}