Feature/httpd (#94)

* Stub code for http server

* can send a response, cannot process body yet

* write headers to the response

* remove commented code

* add simple test + set default http handler

* tweak CI + unittest

* add missing file

* rewrite http::trim in a simple way

* doc

ws/CMakeLists.txt

@@ -68,6 +68,7 @@ add_executable(ws
   ws_cobra_to_statsd.cpp
   ws_cobra_to_sentry.cpp
   ws_snake.cpp
+  ws_httpd.cpp
   ws.cpp)
 
 target_link_libraries(ws ixwebsocket)