load balancer implementation, code refactoring

server/internal/worker.go

@@ -0,0 +1,15 @@
+package internal
+
+type Worker struct {
+	requests chan Process // downloads to do
+	pending  int          // downloads pending
+	index    int          // index in the heap
+}
+
+func (w *Worker) Work(done chan *Worker) {
+	for {
+		req := <-w.requests
+		req.Start()
+		done <- w
+	}
+}