Add test of recursion limit
Add test of recursion limit

Currently fails:

    error: recursion limit reached while expanding `$crate::__parse_ensure!`
      --> tests/test_ensure.rs:50:22
       |
    50 |       let test = || Ok(ensure!(
       |  ______________________^
    51 | |         false | false | false | false | false | false | false | false | false |
    52 | |         false | false | false | false | false | false | false | false | false |
    53 | |         false | false | false | false | false | false | false | false | false |
    ...  |
    57 | |         false | false | false | false | false | false | false | false | false
    58 | |     ));
       | |_____^
       |
       = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`test_ensure`)
       = note: this error originates in the macro `$crate::__parse_ensure` (in Nightly builds, run with -Z macro-backtrace for more info)

dtolnay/anyhow