Remove deprecated lowest_layer from test::stream.

refs #1934

CHANGELOG.md

@@ -1,3 +1,4 @@
+* Remove deprecated lowest_layer from test::stream
 * Remove handler_pointer (API Change)
 * Remove websocket::role_type (API Change)
 * Remove accept_ex and handshake_ex variants (API Change)

include/boost/beast/_experimental/test/stream.hpp

@@ -186,27 +186,6 @@ class stream
         std::unique_ptr<read_op_base>&& op,
         std::size_t buf_size);
 
-#if ! BOOST_BEAST_DOXYGEN
-    // boost::asio::ssl::stream needs these
-    // DEPRECATED
-    template<class>
-    friend class boost::asio::ssl::stream;
-    // DEPRECATED
-    using lowest_layer_type = stream;
-    // DEPRECATED
-    lowest_layer_type&
-    lowest_layer() noexcept
-    {
-        return *this;
-    }
-    // DEPRECATED
-    lowest_layer_type const&
-    lowest_layer() const noexcept
-    {
-        return *this;
-    }
-#endif
-
 public:
     using buffer_type = flat_buffer;