Disable authentication

[davidcie]

Had a look at both readme and code and it seems that, unless using a secret, both encryptionKey and signingKey are required and, essentially, both encryption and authentication are turned on by default.

In our case encryption is more than enough protection and we'd prefer to disable authentication for a small perf gain. Is this deliberate and the direction you want to take this plugin in or are you open to discussion on having auth optional?

[joegoldbeck]

@davidcie That's a good point! In general, I want to keep the number of code paths minimal, but this seems fairly reasonable. Feel free to submit a PR with a skipAuthentication option and associated tests/docs, and I'll make an effort to turn it around quickly. Seems like it shouldn't be too bad, let me know if you have any questions.

[davidcie]

Thanks! Hope to find the time sometime later this week.

In our particular case we're trying to keep the size of each document down because the number of them is rather large. Hence every byte we can save per document translates to a couple thousand bytes not transferred over the wire.