Update ListUsersOptions: add missing parameters (#388)

* Update ListUsersOptions: add provider and createdafter

* Update ListUsersOptions: add order_by and sort

users.go

@@ -82,7 +82,11 @@ type ListUsersOptions struct {
 	Search        *string    `url:"search,omitempty" json:"search,omitempty"`
 	Username      *string    `url:"username,omitempty" json:"username,omitempty"`
 	ExternalUID   *string    `url:"extern_uid,omitempty" json:"extern_uid,omitempty"`
-	CreatedBefore *time.Time `url:"created_before,omitempty" json:"created_before,omitempty" `
+	Provider      *string    `url:"provider,omitempty" json:"provider,omitempty"`
+	CreatedBefore *time.Time `url:"created_before,omitempty" json:"created_before,omitempty"`
+	CreatedAfter  *time.Time `url:"created_after,omitempty" json:"created_after,omitempty"`
+	OrderBy       *string    `url:"order_by,omitempty" json:"order_by,omitempty"`
+	Sort          *string    `url:"sort,omitempty" json:"sort,omitempty"`
 }
 
 // ListUsers gets a list of users.