Add Error Handling

[idky137]

Remove any unwraps that have the possibility of returning an error from production code.
Instead handle errors, either re-queuing requests or returning an error message to the client.
For serious system errors possibly implement graceful shutdown or soft restart.

[idky137]

Unwraps have been removed but there are still several "TODO's" that need to be replaced with correct error handling logic.

[idky137]

This work will be completed in #67