Cannot install on MacOS

[trueb2]

The install instructions for MacOS reference a mezmo-agent package that does not exist.

[jakedipity]

MacOS support was only just added in 3.9 but we're still working on finalizing our build pipeline and brew release process. We'll mark this issue complete once the brew package has been released.

In the meantime we do have the packages for the 3.9.0 release are available at

1. x86_64: https://logdna-agent-build-bin.s3.amazonaws.com/3.9.0/logdna-agent-3.9.0-x86.pkg
2. arm64: https://logdna-agent-build-bin.s3.amazonaws.com/3.9.0/logdna-agent-3.9.0-arm64.pkg