Increase time "added" for single node test

Wait()ing for the log the be applied can take 2 loops. Due to this the
timer used to trigger the 3rd check is pushed too far into the future.
So push the clock even farther into the future.

As a result, all Travis testing can be re-enabled.
Merge pull request #1174 from otoolep/increase_add_time

Increase time "added" for single node test