Adds example with "open loop" policy

- Adds WebClusterDatabaseOpenLoopExample, which sends an SMS message
  when the max-pool-size cap is reached. This notification to the
  operator allows someone to manually reconfigure the AutoScaler policy
  to increase the max-pool-size, if desired.
Merge pull request #515 from aledsage/feature/Example-OpenLoopPolicy

example open loop policy