FIX: small diverse fixes (#35)

base/src/test/user_model/test_to_from_bytes.rs

@@ -25,6 +25,6 @@ fn errors() {
     let model_bytes = "Early in the morning, late in the century, Cricklewood Broadway.".as_bytes();
     assert_eq!(
         &UserModel::from_bytes(model_bytes).unwrap_err(),
-        "Error parsing workbook"
+        "Error parsing workbook: invalid packing"
     );
 }