Add argument parser for the conduit executable

Allow fetching the version with `conduit --version`. Fixes #285.

src/clap.rs

@@ -0,0 +1,13 @@
+//! Integration with `clap`
+
+use clap::Parser;
+
+/// Command line arguments
+#[derive(Parser)]
+#[clap(about, version)]
+pub struct Args {}
+
+/// Parse command line arguments into structured data
+pub fn parse() -> Args {
+    Args::parse()
+}

src/lib.rs

@@ -1,4 +1,5 @@
 pub mod api;
+pub mod clap;
 mod config;
 mod database;
 mod service;

src/main.rs

@@ -44,6 +44,8 @@ static GLOBAL: Jemalloc = Jemalloc;
 
 #[tokio::main]
 async fn main() {
+    clap::parse();
+
     // Initialize config
     let raw_config =
         Figment::new()