Document Lambda CloudWatch requirement

[Matt Olenik]

Because of the CloudWatch metrics, Lambdas won't run without CloudWatch. It's non-obvious to debug this, especially for someone unfamiliar with AWS. It'd be nice to at least have it documented, or offer an env var to shut off CW metrics.

[Waldemar Hummer]

Thanks for reporting, this is fixed in commit b8180317e4b710ca85479d88abed6b66d800c9f2. Metrics are now only forwarded if the CloudWatch service is actually started. Closing this issue now, please re-open if the problem persists. Thanks