Add mcs admin trace api (#82)

Trace Api uses websocket to send trace information, a
valid jwt token needs to be sent either on the header
or as a cookie of the ws request to start.
Three goroutines are needed to ensure communication
if read hearbeat fails all trace should stop by cancelling
the context. WaitGroups are needed to ensure all
goroutines finish gracefully.

restapi/embedded_spec.go

@@ -42,7 +42,8 @@ func init() {
     "application/json"
   ],
   "schemes": [
-    "http"
+    "http",
+    "ws"
   ],
   "swagger": "2.0",
   "info": {
@@ -2032,7 +2033,8 @@ func init() {
     "application/json"
   ],
   "schemes": [
-    "http"
+    "http",
+    "ws"
   ],
   "swagger": "2.0",
   "info": {