Send SIGINT on Ctrl+C instead of immediate exit

lib/dashboard.js

@@ -52,7 +52,7 @@ Dashboard.prototype._configureKeys = function () {
   // this key will be watched on the global screen
   this.screen.ignoreLocked = ["C-c"];
   this.screen.key("C-c", function () {
-    process.exit(0); // eslint-disable-line no-process-exit
+    process.kill(process.pid, "SIGINT");
   });
 
   // watch for key events on the main container; not the screen