Output retool apps errors to stderr

[masaru-iritani]

What

Use console.error instead of console.log to output errors of retool apps.

Why

I'm thinking of adding --json option to retool apps for outputting results in JSON. For that, it's important to differentiate standard outputs from errors. As the initial step, this change replaces all console.log outputting errors with console.error to redirect error messages to stderr, not stdout.

In addition, console.error renders messages in red, so errors stand out more.

How tested

An error message is rendered in red when stdout is redirected to /dev/null.

$ yes | ./lib/index.js apps --delete non_existing_app > /dev/null
0 or >1 Apps named non_existing_app found. 😓