Clone the problem specifications into a subdirectory if it doesn't already exist
Clone the problem specifications into a subdirectory if it doesn't already exist

This enables us to point configlet at a known location where it should exist,
which in turn should make Travis happier with this.

exercism/xrust,sacherjj/rust,petertseng/exercism-rust,exercism/xrust,petertseng/exercism-rust,sacherjj/rust,petertseng/exercism-rust,sacherjj/rust