Add a test to encourage taking care with thrift changes.

We have more to do w.r.t. automating detection and proper handling of schema
changes (specifically in the scheduler).  However, i see this as low-hanging
fruit to at least serve as a reminder.

Reviewed at https://reviews.apache.org/r/16986/
Revert "Add a test to encourage taking care with thrift changes."

This reverts commit 621eb53f40713b484730763860cdfbba0362e120.
Add keys file for signed release.

Bugs closed: AURORA-49

Reviewed at https://reviews.apache.org/r/17025/