Fix argument parsing and update deps (#114)

- Fix argument parsing
- Bump dependencies
- Change to Blue Oak license
- Add caching to CI

Resolves #110

Author: lhvy

.github/workflows/ci.yaml

@@ -34,6 +34,9 @@ jobs:
           profile: minimal
           components: clippy
 
+      - name: Load Rust/Cargo cache
+        uses: Swatinem/rust-cache@v2
+
       - name: Build
         uses: actions-rs/cargo@v1
         with: