Drag and drop columns not working

[jhefreyzz]

Hi,

When I try to run the card board example in the demo the dragging and dropping of columns does not work.

I also copied the cards component from https://github.com/kutlugsahin/vue-smooth-dnd/blob/master/demo/src/pages/cards.vue.

I also check the two packages my local copy and demo and it has the same vue-smooth-dnd version.

{
  "name": "flow",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "serve": "vue-cli-service serve",
    "build": "vue-cli-service build",
    "lint": "vue-cli-service lint"
  },
  "dependencies": {
    "core-js": "^3.3.2",
    "vue": "^2.6.10",
    "vue-router": "^3.1.3",
    "vue-smooth-dnd": "^0.8.1",
    "vuex": "^3.0.1"
  },
  "devDependencies": {
    "@vue/cli-plugin-babel": "^4.0.0",
    "@vue/cli-plugin-eslint": "^4.0.0",
    "@vue/cli-plugin-router": "^4.0.0",
    "@vue/cli-plugin-vuex": "^4.0.0",
    "@vue/cli-service": "^4.0.0",
    "@vue/eslint-config-prettier": "^5.0.0",
    "babel-eslint": "^10.0.3",
    "eslint": "^5.16.0",
    "eslint-plugin-prettier": "^3.1.1",
    "eslint-plugin-vue": "^5.0.0",
    "prettier": "^1.18.2",
    "sass": "^1.19.0",
    "sass-loader": "^8.0.0",
    "vue-template-compiler": "^2.6.10"
  }
}

I also attach a gif for the issue.