Update Justfile docker start command for backend

 * TIL that Just handles parsing `.env` files automatically.
 * Add some additional environment variables
 * Pass through `$PORT` correctly rather than using `$ROCKET_PORT`
  * The Dockerfile's default command itself maps `$PORT` to `$ROCKET_PORT` explicitly

backend/Justfile

@@ -7,5 +7,6 @@ spawn_redis:
   docker run --rm -d -p 6379:6379 --name redis redis
 
 docker_start:
-  export $(egrep -v '^#' .env | xargs)
-  docker run -it --net host -p 3999:3999 -e ROCKET_DATABASES="{ spotify_homepage = { url = \"$DATABASE_URL\" } }" -e "ROCKET_PORT=3999" -e SPOTIFY_CLIENT_ID="$SPOTIFY_CLIENT_ID" -e SPOTIFY_CLIENT_SECRET="$SPOTIFY_CLIENT_SECRET" -e SERVER_BASE_URL="$SERVER_BASE_URL" -e REDIS_URL="$REDIS_URL" --name spotifytrack-server ameo/spotify-homepage-backend
+  docker rm spotifytrack-server || true
+  echo "$SPOTIFY_CLIENT_ID"
+  docker run -it --net host -p 3999:3999 -e ROCKET_DATABASES="{ spotify_homepage = { url = \"$DATABASE_URL\" } }" -e PORT="$PORT" -e SPOTIFY_CLIENT_ID="$SPOTIFY_CLIENT_ID" -e SPOTIFY_CLIENT_SECRET="$SPOTIFY_CLIENT_SECRET" -e SERVER_BASE_URL="$SERVER_BASE_URL" -e REDIS_URL="$REDIS_URL" -e ADMIN_API_TOKEN="$ADMIN_API_TOKEN" --name spotifytrack-server ameo/spotify-homepage-backend