remove doc test for helpers (for now)

src/helpers.rs

@@ -1,19 +1,3 @@
-/// helper functions for common decode scenarios
-/// ## Eample
-/// ```
-/// use rxing;
-/// 
-/// fn main() {
-///     let file_name = "test_image.jpg";
-/// 
-///     let results = rxing::helpers::detect_multiple_in_file(file_name).expect("decodes");
-/// 
-///     for result in results {
-///         println!("{} -> {}", result.getBarcodeFormat(), result.getText())
-///     }
-/// }
-///  ```
-
 use std::{
     collections::{HashMap, HashSet},
     rc::Rc,