Console warnings are not being transpiled for the dist

[samboylett]

Describe the bug

Useful console messages are not being transpiled into the dist, e.g.:
https://github.com/sagalbot/vue-select/blob/master/src/components/Select.vue#L245

To Reproduce
Steps to reproduce the behavior:

1. Go to the repo
2. run yarn
3. run yarn build
4. Search dist/vue-select.js for console

Expected behavior
Don't minify/remove the console functions in the distribution code (this can be handled by peoples app build anyway). Or throw an error instead.

Additional context
So I found this issue as I have options set to an array of objects and am rendering the label using the slot instead of the prop. Issue is when trying to select a different option, it uses isOptionSelected/optionComparator to compare the objects, but getOptionLabel was returning undefined. I don't really consider this to be the bug as I was missing config, but having the console.warn would have really helped me to debug this. This is definitely a weird edge case / gotcha that should be considered though.