Start to write e2e tests

src/test/mod.rs

@@ -0,0 +1,15 @@
+#[non_exhaustive]
+enum PortsAllocation {
+    DummyTCPServer,
+    ValidWithTokenAuth,
+}
+
+fn get_port_number(alloc: PortsAllocation, index: u16) -> u16 {
+    2100 + 20 * (alloc as u16) + index
+}
+
+const LOCALHOST: &str = "127.0.0.1";
+
+mod dummy_tcp_sockets;
+
+mod valid_with_token_auth;