Boost beast

This commit is the beginings of attempting to transition away from
crow, and toward boost::beast.  Unit tests are passing, and
implementation appears to be slightly faster than crow.

Change-Id: Ic8d946dc7a04f514c67b1098f181eee1ced69171
diff --git a/src/kvm_websocket_test.cpp b/src/kvm_websocket_test.cpp
index d3ab54d..94a9ffc 100644
--- a/src/kvm_websocket_test.cpp
+++ b/src/kvm_websocket_test.cpp
@@ -17,7 +17,7 @@
 
   crow::kvm::request_routes(app);
   app.bindaddr("127.0.0.1").port(45451);
-  CROW_ROUTE(app, "/")([]() { return 200; });
+  CROW_ROUTE(app, "/")([]() { return boost::beast::http::status::ok; });
   auto _ = async(std::launch::async, [&] { app.run(); });
   auto routes = app.get_routes();
   asio::io_service is;