Suggestion: brew upgrade fails with 1 because of advisories that Dorothy already handles

[balupton]

Re-running brew upgrade, or rather setup-system update / setup-mac-brew update resolves these issues, as the advisories are not actually errors, and Dorothy already handles the advisories, which is the point.

Based on earlier feedback Dorothy now starts the brew upgrade process with this message:

Brew upgrades can fail sporadically due to changes in the environment (such as when the environment depended on a now upgraded package, in which the environment must be reloaded to make use of the upgraded package). If it fails, open a new terminal and try again which will continue this incremental upgrade process.

However, long upgrades of many packages makes that message non-noticeable in practice.

Instead, we should detect the error status, and if 1 then we should provide a confirmation to the user telling them that unless there is actually an error, it is safe to continue, and would they like to continue?