GetRealmsIndexAsync() failing for TW

[bonesoul]

basically I do have an client & secret for us endpoints.

using these api client id and secret values i can make calls to all realms except tw:

var result = await client.GetRealmsIndexAsync(@namespace);

16:39:22 [INF] [RealmUpdater] querying realms of taiwan failed with System.Net.Http.HttpRequestException: Response code 401 (Unauthorized) does not indicate success. Request: https://tw.api.blizzard.com/data/wow/realm/index?namespace=dynamic-tw&locale=zh_TW
   at ArgentPonyWarcraftClient.WarcraftClient.GetAsync[T](String requestUri, String accessToken)
   at ArgentPonyWarcraftClient.WarcraftClient.GetAsync[T](String requestUri)
   at ArgentPonyWarcraftClient.WarcraftClient.GetRealmsIndexAsync(String namespace, Region region, Locale locale)
   at ArgentPonyWarcraftClient.WarcraftClient.GetRealmsIndexAsync(String namespace)
   at Wowtrack.Data.Updater.Jobs.Realm.RealmUpdater.GetRealmsForRegion(Region region, Locale locale) in C:\Coding\wowtrack.gg\core_dotnet\src\tools\updater\Jobs\Realm\RealmUpdater.cs:line 106..

tw version fails:

https://tw.api.blizzard.com/data/wow/realm/index?namespace=dynamic-tw&locale=zh_TW&access_token=TOKEN

[bonesoul]

I have further debugged the issue, the library can't get an access token for tw:

yet again caused by:

[bonesoul]

seems the issue caused by because that endpoints changed:

https://develop.battle.net/documentation/guides/using-oauth

US, EU, APAC | https://oauth.battle.net/authorize | https://oauth.battle.net/token

once if fix the host as https://apac.battle.net it just works.

[bonesoul]

created a pr for this: #212

[bonesoul]

doc now suggests https://develop.battle.net/documentation/guides/using-oauth for EU, US and APAC regions.

[bonesoul]

updated the PR for according to latest oauth host changes.