fix: don't allow empty strings to be selected (#1595)

src/components/Select.vue

@@ -702,7 +702,7 @@ export default {
         value = this.$data._value
       }
 
-      if (value !== undefined && value !== null) {
+      if (value !== undefined && value !== null && value !== '') {
         return [].concat(value)
       }
 

tests/unit/Selecting.spec.js

@@ -213,7 +213,7 @@ describe('VS - Selecting Values', () => {
     expect(Select.vm.selectedValue).toEqual(options)
   })
 
-  fit('can select a false boolean option', async () => {
+  it('can select a false boolean option', async () => {
     const Select = mountDefault({
       options: [false],
     })