added methods with context + upgrad go version

[crayonwow]

add methods that allows pass context to calls upgraded go version up to 1.19

[OsoianMarcel]

The initiative to implement the Context is welcome, thank you. Without context, the long polling HTTP requests are not cancelable, so for graceful shutdown, the app needs to wait from 0 to 60 seconds.

Dear author, thank you for the library, I find it the most easy to use.