Load LogSubscribers on demand.

Prior to this change, all LogSubscribers were loaded and used. Now, only
the needed LogSubscribers are loaded
Provide a clear error when you forgot to specify an encryptor
Merge pull request #21 from jmazzi/bugfix/missing_encryptor

Provide a clear error when you forgot to specify an encryptor
Merge pull request #20 from jmazzi/refactor/log_subscribers

Attach log subscribers on-demand
Spec cleanups
Ignore bin
Gem updates
Merge pull request #22 from jmazzi/refactor/cleanup_specs

Spec cleanups
Merge pull request #23 from jmazzi/gemupdates

Update gems