Automate syncing test

[theoreticalbts]

We need a script that spins up a steemd process, monitors it, and shuts it down. After shutdown the script should exit 0 (if sync was successful) or exit 1 (if sync was unsuccessful).

Basically it should check every ~3 minutes:

• Has my head block number advanced from the last check? If not, exit with error.
• Is my head block time close to the present actual time? If so, exit with success.

[sneak]

suggestion: output useful messages only, perhaps by grep -ving output for common/nominal messages so it only outputs stuff we care about for testing/debugging.

[mvandeberg]

steemdsync sort of takes care of this already.