Clean up worker service (#272)

* Remove Java project from worker

* Update .NET Core and remove old dotnet codebase from worker service

* Remove Windows-based Compose files and info from README

* Update .NET to 7.0

Author: mikesir87

README.md

@@ -11,7 +11,7 @@ Download [Docker Desktop](https://www.docker.com/products/docker-desktop) for Ma
 
 ## Linux Containers
 
-The Linux stack uses Python, Node.js, .NET Core (or optionally Java), with Redis for messaging and Postgres for storage.
+The Linux stack uses Python, Node.js, .NET Core, with Redis for messaging and Postgres for storage.
 
 > If you're using [Docker Desktop on Windows](https://store.docker.com/editions/community/docker-ce-desktop-windows), you can run the Linux version by [switching to Linux containers](https://docs.docker.com/docker-for-windows/#switch-between-windows-and-linux-containers), or run the Windows containers version.
 
@@ -30,26 +30,6 @@ Once you have your swarm, in this directory run:
 docker stack deploy --compose-file docker-stack.yml vote
 ```
 
-## Windows Containers
-
-An alternative version of the app uses Windows containers based on Nano Server. This stack runs on .NET Core, using [NATS](https://nats.io) for messaging and [TiDB](https://github.com/pingcap/tidb) for storage.
-
-You can build from source using:
-
-```
-docker compose -f docker-compose-windows.yml build
-```
-
-Then run the app using:
-
-```
-docker compose -f docker-compose-windows.yml up -d
-```
-
-> Or in a Windows swarm, run `docker stack deploy -c docker-stack-windows.yml vote`
-
-The app will be running at [http://localhost:5000](http://localhost:5000), and the results will be at [http://localhost:5001](http://localhost:5001).
-
 
 Run the app in Kubernetes
 -------------------------
@@ -85,7 +65,7 @@ Architecture
 
 * A front-end web app in [Python](/vote) or [ASP.NET Core](/vote/dotnet) which lets you vote between two options
 * A [Redis](https://hub.docker.com/_/redis/) or [NATS](https://hub.docker.com/_/nats/) queue which collects new votes
-* A [.NET Core](/worker/src/Worker), [Java](/worker/src/main) or [.NET Core 2.1](/worker/dotnet) worker which consumes votes and stores them in…
+* A [.NET Core](/worker/) worker which consumes votes and stores them in…
 * A [Postgres](https://hub.docker.com/_/postgres/) or [TiDB](https://hub.docker.com/r/dockersamples/tidb/tags/) database backed by a Docker volume
 * A [Node.js](/result) or [ASP.NET Core SignalR](/result/dotnet) webapp which shows the results of the voting in real time