fix(reduce): reduce + taggable bug (#1091)

Resolves #1089
Resolves #993

tests/unit/Reduce.spec.js

@@ -226,4 +226,33 @@ describe("When reduce prop is defined", () => {
 
     expect(Select.vm.selectedValue).toEqual([optionToChangeTo]);
   });
+
+  describe('Reducing Tags', () => {
+    it('tracks values that have been created by the user', async () => {
+      const Parent = mount({
+        data: () => ({selected: null, options: []}),
+        template: `
+          <v-select
+            v-model="selected"
+            :options="options"
+            taggable
+            :reduce="name => name.value"
+            :create-option="label => ({ label, value: -1 })"
+          />
+        `,
+        components: {'v-select': VueSelect},
+      });
+      const Select = Parent.vm.$children[0];
+
+      //  When
+      Select.search = 'hello';
+      Select.typeAheadSelect();
+      await Select.$nextTick();
+
+      //  Then
+      expect(Select.selectedValue).toEqual([{label: 'hello', value: -1}]);
+      expect(Select.$refs.selectedOptions.textContent.trim()).toEqual('hello');
+      expect(Parent.vm.selected).toEqual(-1);
+    });
+  });
 });