Specify panic="abort"

exa doesn’t capture any failures — it’s not really worth it for such a short-lived task, and doing this results in a smaller binary.

Fixes #128.

Cargo.toml

@@ -35,6 +35,7 @@ git = [ "git2" ]
 opt-level = 3
 debug = false
 lto = true
+panic = "abort"
 
 [dependencies.git2]
 version = "0.6.4"