Use rune when delete or filter answer

[AielloChan]

When using Unicode in the string type answer will cause a problem.

Example:

> go run examples/simple.go
? What is your name? 小明

[AlecAivazis]

Hey @AielloChan! Thanks for submitting this fix, would you mind adding a test that shows the problem is fixed?

[AielloChan]

Check if that is ok😬

[AlecAivazis]

Okay, I finally found some time to pull this down and give it a shot. Thanks for being patient!

Everything seems to behave correctly on my machine, however since this touches a bunch of prompts, i'd like to get a second pair of eyes on it. Maybe @coryb or @mislav have some spare time?

[AlecAivazis]

Hm, I might be missing something but wouldn't this also affect the Select prompt?

[AielloChan]

Hm, I might be missing something but wouldn't this also affect the Select prompt?

Yes, because prompt filter also need use Rune for unicode words.

[mislav]

This looks good to me!

[AlecAivazis]

great! thanks for taking a look @mislav