Purpose
=======

Given a QR code representing a TOTP auth key:
 1. Decode the QR code and print the full contents.
 2. Print the TOTP response for the current time.

Building
========

You will need Rust: https://www.rust-lang.org/

For a development build: use `cargo build`; the executable will be
located at `target/debug/de2fa`.

For a production build, use `cargo build --release`. The executable will
be located at `target/release/de2fa`.

For usage, invoke the executable with `--help`.