exchange names need escaping

[mijabr]

Seems DeleteBindingAsync() does not handle the case where source/destination has a colon in the name. I get a 404 when trying to delete.

Examining the request I see

http://localhost:15672/api/bindings/%2F/e/My:Exchange1/e/My:Exchange1/~

but it should be

http://localhost:15672/api/bindings/%2F/e/My%3AExchange1/e/My%3AExchange1/~

Looks like an addition to SanitiseName() and include it DeleteBindingAsync() for source/destination names.

Can I give you a pull request for this?