Ignore unreadable_literal pedantic clippy lint in test

    warning: long literal lacking separators
        --> tests/test_expr.rs:1189:23
         |
    1189 |     assert_eq!(count, 133539);
         |                       ^^^^^^ help: consider: `133_539`
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unreadable_literal
         = note: `-W clippy::unreadable-literal` implied by `-W clippy::pedantic`
         = help: to override `-W clippy::pedantic` add `#[allow(clippy::unreadable_literal)]`

tests/test_expr.rs

@@ -3,7 +3,8 @@
     clippy::needless_lifetimes,
     clippy::single_element_loop,
     clippy::too_many_lines,
-    clippy::uninlined_format_args
+    clippy::uninlined_format_args,
+    clippy::unreadable_literal
 )]
 
 #[macro_use]