IPVanish support (#475)

- Fix #410 and #416

internal/storage/merge.go

@@ -36,6 +36,7 @@ func (s *storage) mergeServers(hardcoded, persisted models.AllServers) models.Al
 		Cyberghost:   s.mergeCyberghost(hardcoded.Cyberghost, persisted.Cyberghost),
 		Fastestvpn:   s.mergeFastestvpn(hardcoded.Fastestvpn, persisted.Fastestvpn),
 		HideMyAss:    s.mergeHideMyAss(hardcoded.HideMyAss, persisted.HideMyAss),
+		Ipvanish:     s.mergeIpvanish(hardcoded.Ipvanish, persisted.Ipvanish),
 		Ivpn:         s.mergeIvpn(hardcoded.Ivpn, persisted.Ivpn),
 		Mullvad:      s.mergeMullvad(hardcoded.Mullvad, persisted.Mullvad),
 		Nordvpn:      s.mergeNordVPN(hardcoded.Nordvpn, persisted.Nordvpn),
@@ -93,6 +94,19 @@ func (s *storage) mergeHideMyAss(hardcoded, persisted models.HideMyAssServers) m
 	return persisted
 }
 
+func (s *storage) mergeIpvanish(hardcoded, persisted models.IpvanishServers) models.IpvanishServers {
+	if persisted.Timestamp <= hardcoded.Timestamp {
+		return hardcoded
+	}
+	versionDiff := hardcoded.Version - persisted.Version
+	if versionDiff > 0 {
+		s.logVersionDiff("Ipvanish", versionDiff)
+		return hardcoded
+	}
+	s.logTimeDiff("Ipvanish", persisted.Timestamp, hardcoded.Timestamp)
+	return persisted
+}
+
 func (s *storage) mergeIvpn(hardcoded, persisted models.IvpnServers) models.IvpnServers {
 	if persisted.Timestamp <= hardcoded.Timestamp {
 		return hardcoded

internal/storage/sync.go

@@ -21,6 +21,7 @@ func countServers(allServers models.AllServers) int {
 	return len(allServers.Cyberghost.Servers) +
 		len(allServers.Fastestvpn.Servers) +
 		len(allServers.HideMyAss.Servers) +
+		len(allServers.Ipvanish.Servers) +
 		len(allServers.Ivpn.Servers) +
 		len(allServers.Mullvad.Servers) +
 		len(allServers.Nordvpn.Servers) +