v2.1.0

• feat(SidebarNav): navLink attributes - optional JS object with valid JS API naming:
  • attributes: rel, target, hidden, disabled, etc…
  • starting with @coreui/coreui ^2.1.4, @coreui/vue ^2.1.0
  • item example(./src/_nav.js):

{
  name: 'Disabled',
  url: '/disabled',
  icon: 'icon-ban',
  attributes: { disabled: true },
},
{
  name: 'Try CoreUI PRO',
  url: 'https://coreui.io/pro/react/',
  icon: 'cui-layers icons',
  variant: 'danger',
  attributes: { target: '_blank', rel: "noopener" },
},

• test: e2e and snapshots update
• chore: update @coreui/coreui-pro to ^2.1.4
• chore: update @coreui/vue to ^2.1.0

• chore: update core-js to ^2.6.0
• chore: update css-vars-ponyfill to ^1.15.3
• chore: update vue to ^2.5.19
• chore: update vue-router to `^3.0.2"
• chore: update vue-template-compiler to ^2.5.19
• chore: update @vue/cli-plugin-babel to ^3.2.0
• chore: update @vue/cli-plugin-e2e-nightwatch to ^3.2.0
• chore: update @vue/cli-plugin-eslint to ^3.2.1
• chore: update @vue/cli-plugin-unit-jest to ^3.2.0
• chore: update @vue/cli-service to ^3.2.0
• chore: update @vue/test-utils to ^1.0.0-beta.27
• chore: update node-sass to ^4.11.0