Connections do not accept transactions using a context

Having there be a mandatory context will just create more waste
and slow stuff down for transports which don't support it.

connection.go

@@ -1,19 +1,19 @@
 package hopp
 
 import "io"
-import "context"
 
 // Conn is a HOPP connection.
 type Conn interface {
 	io.Closer
 	OpenTrans() (Trans, error)
-	AcceptTrans(ctx context.Context) (Trans, error)
+	AcceptTrans() (Trans, error)
 }
 
 // Trans is a HOPP transaction.
 type Trans interface {
 	io.Closer
 	ID() int64
+	
 	// Send sends a message.
 	Send(method uint16, data []byte) error
 	// Receive receives a message.