refactor: make everything a little more modular

src/error.rs

@@ -0,0 +1,27 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub struct ScootalooError {
+    details: String,
+}
+
+impl ScootalooError {
+    pub fn new(msg: &str) -> ScootalooError {
+        ScootalooError {
+            details: String::from(msg),
+        }
+    }
+}
+
+impl fmt::Display for ScootalooError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.details)
+    }
+}
+
+impl std::error::Error for ScootalooError {
+    fn description(&self) -> &str {
+        &self.details
+    }
+}
+