bubble up parsing errors

src/utils.rs

@@ -1,5 +1,14 @@
 use clap::{App, Arg};
 
+#[derive(Debug, thiserror::Error)]
+#[allow(clippy::large_enum_variant)]
+pub enum Error {
+    #[error("cant parse")]
+    CantParse,
+    #[error("general error")]
+    UnknownError,
+}
+
 pub fn cli() -> App<'static, 'static> {
     App::new("ban internets scanner fast 🍶")
         .version("v0.0.1")