macros: Add tests to check for HashMap scoping (#938)
macros: Add tests to check for HashMap scoping (#938)

* macros: Add tests to check for HashMap scoping

This test makes sure that students use `::std::collections::HashMap`
instead of just `std::collections::HashMap`. It is intended
to show that a user can override the intended type.

The receive this error if the wrong scoping is used:

```
---- test_type_override stdout ----
thread 'test_type_override' panicked at 'Don't allow users to override which HashMap is used', tests/macros.rs:82:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

* macros: Properly ignore test, rework test

* Update exercises/macros/tests/macros.rs

Co-Authored-By: Peter Goodspeed-Niklaus <dea3b09e269342fa2efe929fc2dabc7369dca99f@users.noreply.github.com>

Co-authored-by: Peter Goodspeed-Niklaus <dea3b09e269342fa2efe929fc2dabc7369dca99f@users.noreply.github.com>
petertseng/exercism-rust,exercism/xrust,petertseng/exercism-rust,exercism/xrust,petertseng/exercism-rust