chef-automatev2 resource installation guard check fails with Chef Infra 16.1

[gdavison]

When installing Chef Automate v2 with this cookbook, the guard check for the deployment step fails with

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Error executing action `run` on resource 'execute[/usr/local/bin/chef-automate deploy /tmp/kitchen/cache/config.toml --accept-terms-and-mlsa]'
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Errno::ENOENT
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execute[Guard resource] (dynamically defined) had an error: Errno::ENOENT: No such file or directory - chef-automate

In all other invocations of chef-automate the full path is supplied, but it is not in the guard.

Steps to Reproduce

1. Execute CHEF_VERSION=16.1 kitchen test chef-automatev2-centos-7

This same test with Chef Infra v16.2 has a different error: #259