pig-latin: Add empty src/lib.rs (#324)
pig-latin: Add empty src/lib.rs (#324)

Forgot to be added in #319.
Should be added because of #270.
exercism/xrust,sacherjj/rust,petertseng/exercism-rust,sacherjj/rust,petertseng/exercism-rust,exercism/xrust,sacherjj/rust,petertseng/exercism-rust