installs rocket, hello world endpoint

src/main.rs

@@ -1,3 +1,11 @@
-fn main() {
-    println!("Hello, world!");
+#[macro_use] extern crate rocket;
+
+#[launch]
+fn rocket() -> _ {
+    rocket::build().mount("/", routes![index])
+}
+
+#[get("/")]
+fn index() -> &'static str {
+    "Hello, world!"
 }