Support passing ssl_config through

pgx/src/pgx.mli

@@ -49,4 +49,5 @@ module Value = Pgx_value
 
 module type S = Pgx_intf.S
 
-module Make (Thread : Io) : S with type 'a Io.t = 'a Thread.t
+module Make (Thread : Io) :
+  S with type 'a Io.t = 'a Thread.t and type Io.ssl_config = Thread.ssl_config

pgx_async/src/pgx_async.mli

@@ -1,24 +1,14 @@
 (** Async based Postgres client based on Pgx. *)
 open Async_kernel
 
-include Pgx.S with type 'a Io.t = 'a Deferred.t
+include
+  Pgx.S
+    with type 'a Io.t = 'a Deferred.t
+     and type Io.ssl_config = Conduit_async.Ssl.config
 
 (* for testing purposes *)
 module Thread : Pgx.Io with type 'a t = 'a Deferred.t
 
-val with_conn
-  :  ?ssl:[ `Auto | `No | `Always of Io.ssl_config ]
-  -> ?host:string
-  -> ?port:int
-  -> ?user:string
-  -> ?password:string
-  -> ?database:string
-  -> ?unix_domain_socket_dir:string
-  -> ?verbose:int
-  -> ?max_message_length:int
-  -> (t -> 'a Deferred.t)
-  -> 'a Deferred.t
-
 (** Like [execute] but returns a pipe so you can operate on the results before they have all returned.
     Note that [execute_iter] and [execute_fold] can perform significantly better because they don't have
     as much overhead. *)