[md-autocomplete] should hide when losing focus via TAB or clicking another field

[gotson]

#1978 # Steps to reproduce

Using any example from the documentation: https://vuematerial.io/components/autocomplete

Focus on a field, type a few letters that are matching some items in the list, and then hit tab, or click another input field.

Which browser?

Chrome 72

What is expected?

The autocomplete list should disappear.

What is actually happening?

The autocomplete list does not disappear.