Upgrade command incorrectly displays brew update output as error

[garrytrinder]

Raised from #292

Description

The upgrade command in Dev Proxy Toolkit displays the output of the brew update command before updating the package and incorrectly treats it as an error. The command actually succeeds and Dev Proxy is updated successfully, but the informational message from brew is being displayed as if it were an error.

Steps to Reproduce

1. Run the upgrade command in Dev Proxy Toolkit
2. Observe the error message display showing brew update output
3. Note that the upgrade actually completes successfully

Expected Behavior

The upgrade command should only display error messages when there is an actual error. Informational messages from brew update should not be treated as errors or displayed to the user unless there's a real failure.

Actual Behavior

The command displays informational output from brew update as an error message, even though the upgrade process completes successfully.

Additional Information

• The upgrade functionality works correctly despite the misleading error display
• This affects the user experience by showing false error information
• Source: Dev Proxy Toolkit