aiken new: Try to get the latest tag of stdlib

crates/aiken-project/src/github/mod.rs

@@ -0,0 +1 @@
+pub mod repo;

crates/aiken-project/src/github/repo.rs

@@ -0,0 +1,22 @@
+use reqwest::{blocking::Client, header::USER_AGENT, Error};
+use serde::Deserialize;
+
+#[derive(Deserialize)]
+pub struct LatestRelease {
+    pub tag_name: String,
+}
+
+impl LatestRelease {
+    pub fn of<Repo: AsRef<str>>(repo: Repo) -> Result<Self, Error> {
+        Ok({
+            Client::new()
+                .get(format!(
+                    "https://api.github.com/repos/{}/releases/latest",
+                    repo.as_ref()
+                ))
+                .header(USER_AGENT, "aiken")
+                .send()?
+                .json::<Self>()?
+        })
+    }
+}