role_type is in boost/beast/core/role.hpp (API Change):

This enumeration is now part of the library core and
not specific to websocket.

test/beast/websocket/CMakeLists.txt

@@ -32,7 +32,6 @@ add_executable (tests-beast-websocket
     read2.cpp
     read3.cpp
     rfc6455.cpp
-    role.cpp
     stream.cpp
     stream_base.cpp
     stream_explicit.cpp

test/beast/websocket/Jamfile

@@ -22,7 +22,6 @@ local SOURCES =
     read2.cpp
     read3.cpp
     rfc6455.cpp
-    role.cpp
     stream.cpp
     stream_base.cpp
     stream_explicit.cpp

test/beast/websocket/role.cpp

@@ -1,11 +0,0 @@
-//
-// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
-//
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//
-// Official repository: https://github.com/boostorg/beast
-//
-
-// Test that header file is self-contained.
-#include <boost/beast/websocket/role.hpp>