Set the default of value to empty string

[schwarmco]

This will fix a bug, i've came across, when giving an undefined value to v-model.

See: https://codepen.io/anon/pen/vPgeRM

[coveralls]

Pull Request Test Coverage Report for Build 54

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.02%) to 70.408%

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Totals
Change from base Build 38:	1.02%
Covered Lines:	48
Relevant Lines:	68

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💛 - Coveralls

[mattzollinhofer]

I'm just plowing through the obvious problems right now to get those fixed/merged. I'm not sure I totally understand the problem here. Can you give me a little more information about the issue?

I've recently merged in some code to a new version of this project. Can you give that a shot and let me know if you're still having trouble?

You can find the new version on NPM here: https://www.npmjs.com/package/vue-typeahead-bootstrap or github here: https://github.com/mattzollinhofer/vue-typeahead-bootstrap.