v0.11.0-beta.2

Release v0.11.0-beta.2

Add flags to customize ping type decisions

Context:
Healthchecks added a "log" ping type to cater to use cases where a
periodic command is likely to exit with failure status but expected to
eventually succeed in future instantiations.
healthchecks/healthchecks#525 (comment)

Problems:
- "log" ping type is not supported.
- Let the user decide ping type to be sent for success, nonzero exit, or
  execution failure (e.g. command not found, no permission, system ran
  out pids, ...)

Changes:
- Introduce three new flags:
  + -on-success: ping type type to send when command exits successfully.
                 defaults to "success".
  + -on-nonzero-exit: ping type to send when command exits with nonzero code.
                      defaults to "exit-code".
  + -on-exec-fail: ping type to send when runitor cannot execute the command.
                   defaults to "fail"
  + valid values for these flags are: "exit-code", "success", "fail", "log".

- Addresses lack of "log" ping type support and use case in #65.