server: new backend

This CR adds a new backend based on TypeScript, Express, WebSocket and
Rollup.
To build the server:
> npm run build
To develop with dev mode:
> npm run start

GitLab: #47
Change-Id: I6cdacab14104ea67c559e3f9e892fbc1b17a022d
diff --git a/.gitignore b/.gitignore
index 8a1dffa..8efb376 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 node_modules/
 dist/
+tsconfig.tsbuildinfo
 
 jaas-client/package-lock.json
 jaas-client/node_modules/