Webdriver_cohttp_async.SessionFor creating and deleting sessions manually.
A Session is a connection to the remote WebDriver browser (server).
val make : host:string -> Capabilities.t -> (session * json) iomake ~host cap creates a new session on host with the required capabilities. It returns the created session and a json describing the available capabilities of the session.
val delete : unit cmddelete ~session closes the session and remove all of its windows, cookies, etc.