Need to support different endpoint for luis publish

[hibrenda]

User would like to publish the luis to mooncake.
eg. chinaeast2 region is targeting https://chinaeast2.api.cognitive.azure.cn instead of https://${region}.api.cognitive.microsoft.com.

So need to support different endpoint for luispublish
microsoft/botframework-cli#778

[feich-ms]

CLI now supports to specify endpoint in build function, please help to update composer side to consume it @lei9444