Check Composer Auth Token before install

### Description

When supplied a Github token for composer authentication, we should run a simple check on the token before the composer install to verify that the token is still valid. This saves us from a flood of failing installs, and avoids wasting time on an install that has no chance of completing successfully.

### Use Case

When we have installs that require auth tokens, we set expiry dates for those tokens, and having a human readable error message letting us know that our token has expired is valuable.