Remove the solution from the stub file of deprecated two-fer (#1267)
Remove the solution from the stub file of deprecated two-fer (#1267)

* Blank out the stub file of deprecated two-fer

* Update exercises/practice/two-fer/src/lib.rs

Co-authored-by: Peter Goodspeed-Niklaus <dea3b09e269342fa2efe929fc2dabc7369dca99f@users.noreply.github.com>

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