add cli for server/client (#4)

This PR adds a CLI to main.rs that allows you to run the redis server and eventually the redis client.

examples/hello_world.rs

@@ -1 +1,4 @@
-
+#[tokio::main]
+async fn main() {
+    unimplemented!();
+}

examples/pub.rs

@@ -1 +1,4 @@
-
+#[tokio::main]
+async fn main() {
+    unimplemented!();
+}