feat(types): add missing types to type definition (#199)

When using typescript on a vue site that has animation, it becomes quite vital to be able to check that they are called. In order to do just that in TS too. I add the missing types.

Author: elevatebart

types/index.d.ts

@@ -108,7 +108,12 @@ interface MountOptions<V extends Vue> extends ComponentOptions<V> {
 
 type ShallowOptions<V extends Vue> = MountOptions<V>
 
+interface VueTestUtilsConfigOptions {
+  stubs?: Stubs
+}
+
 export declare function createLocalVue (): typeof Vue
+export declare let config: VueTestUtilsConfigOptions
 
 export declare function mount<V extends Vue, Ctor extends VueClass<V> = VueClass<V>> (component: Ctor, options?: MountOptions<V>): Wrapper<V>
 export declare function mount<V extends Vue> (component: ComponentOptions<V>, options?: MountOptions<V>): Wrapper<V>
@@ -117,3 +122,6 @@ export declare function mount (component: FunctionalComponentOptions, options?:
 export declare function shallow<V extends Vue, Ctor extends VueClass<V> = VueClass<V>> (component: Ctor, options?: ShallowOptions<V>): Wrapper<V>
 export declare function shallow<V extends Vue> (component: ComponentOptions<V>, options?: ShallowOptions<V>): Wrapper<V>
 export declare function shallow (component: FunctionalComponentOptions, options?: ShallowOptions<Vue>): Wrapper<Vue>
+
+export declare let TransitionStub: Component | string | true  
+export declare let TransitionGroupStub: Component | string | true