Remove rust-crypto, move to libsodium bindings

src/main.rs

@@ -1,7 +1,12 @@
 mod handshake;
 mod types;
 
+use sodiumoxide;
+
 use handshake::Device;
 use types::KeyPair;
 
-fn main() {}
+fn main() {
+    // choose optimal crypto implementations for platform
+    sodiumoxide::init().unwrap();
+}