chore(updater): incorporate FetchServers method in Provider interface

- Each provider interface can now fetch updated servers data
- Rename each provider updater subpackage name to `updater`
- Updater constructor does not take a settings struct
- Updater update method takes in a slice of provider strings

internal/provider/expressvpn/connection_test.go

@@ -87,7 +87,9 @@ func Test_Provider_GetConnection(t *testing.T) {
 				Return(testCase.filteredServers, testCase.storageErr)
 			randSource := rand.NewSource(0)
 
-			provider := New(storage, randSource)
+			unzipper := (common.Unzipper)(nil)
+			warner := (common.Warner)(nil)
+			provider := New(storage, randSource, unzipper, warner)
 
 			if testCase.panicMessage != "" {
 				assert.PanicsWithValue(t, testCase.panicMessage, func() {

internal/provider/expressvpn/provider.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/qdm12/gluetun/internal/constants/providers"
 	"github.com/qdm12/gluetun/internal/provider/common"
+	"github.com/qdm12/gluetun/internal/provider/expressvpn/updater"
 	"github.com/qdm12/gluetun/internal/provider/utils"
 )
 
@@ -12,13 +13,16 @@ type Provider struct {
 	storage    common.Storage
 	randSource rand.Source
 	utils.NoPortForwarder
+	common.Fetcher
 }
 
-func New(storage common.Storage, randSource rand.Source) *Provider {
+func New(storage common.Storage, randSource rand.Source,
+	unzipper common.Unzipper, updaterWarner common.Warner) *Provider {
 	return &Provider{
 		storage:         storage,
 		randSource:      randSource,
 		NoPortForwarder: utils.NewNoPortForwarding(providers.Expressvpn),
+		Fetcher:         updater.New(unzipper, updaterWarner),
 	}
 }
 

internal/provider/expressvpn/updater/hardcoded.go

@@ -1,4 +1,4 @@
-package expressvpn
+package updater
 
 import (
 	"github.com/qdm12/gluetun/internal/models"

internal/provider/expressvpn/updater/resolve.go

@@ -1,4 +1,4 @@
-package expressvpn
+package updater
 
 import (
 	"time"

internal/provider/expressvpn/updater/servers.go

@@ -1,6 +1,6 @@
-// package expressvpn contains code to obtain the server information
+// Package updater contains code to obtain the server information
 // for the ExpressVPN provider.
-package expressvpn
+package updater
 
 import (
 	"context"

internal/provider/expressvpn/updater/updater.go

@@ -1,4 +1,4 @@
-package expressvpn
+package updater
 
 import (
 	"github.com/qdm12/gluetun/internal/provider/common"