add repo parser test

tests/repo/meson.build

@@ -0,0 +1 @@
+tests += {meson.current_source_dir() / 'repo.rs': []}

tests/repo/repo.rs

@@ -0,0 +1,17 @@
+use std::error::Error;
+
+use gentoo_utils::repo::Repo;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let repo = Repo::new("/var/db/repos/gentoo");
+
+    for result in repo.categories()? {
+        let cat = result?;
+
+        for result in cat.ebuilds()? {
+            let _ = result?;
+        }
+    }
+
+    Ok(())
+}