Ignore assertions_on_result_states clippy lint

    error: called `assert!` with `Result::is_err`
      --> tests/test_stmt.rs:48:5
       |
    48 |     assert!(syn::parse_str::<Stmt>("let _ = &raw x;").is_err());
       |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `syn::parse_str::<Stmt>("let _ = &raw x;").unwrap_err()`
       |
       = note: `-D clippy::assertions-on-result-states` implied by `-D clippy::all`
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_result_states

    error: called `assert!` with `Result::is_err`
       --> tests/test_derive_input.rs:396:5
        |
    396 |     assert!(input.attrs[0].parse_meta().is_err());
        |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `input.attrs[0].parse_meta().unwrap_err()`
        |
        = note: `-D clippy::assertions-on-result-states` implied by `-D clippy::all`
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_result_states

    error: called `assert!` with `Result::is_err`
       --> tests/test_derive_input.rs:432:5
        |
    432 |     assert!(input.attrs[0].parse_meta().is_err());
        |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `input.attrs[0].parse_meta().unwrap_err()`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_result_states

tests/test_derive_input.rs

@@ -1,4 +1,4 @@
-#![allow(clippy::too_many_lines)]
+#![allow(clippy::assertions_on_result_states, clippy::too_many_lines)]
 
 #[macro_use]
 mod macros;

tests/test_stmt.rs

@@ -1,4 +1,4 @@
-#![allow(clippy::non_ascii_literal)]
+#![allow(clippy::assertions_on_result_states, clippy::non_ascii_literal)]
 
 #[macro_use]
 mod macros;