$copyText() 方法在ie9，ie10不兼容 about vue-clipboard2

[cassiehuang]

fix the bug by

Vue.prototype.$copyText = function (text, container) {
      return new Promise(function (resolve, reject) {
        var fakeElement = document.createElement('button')
        var clipboard = new Clipboard(fakeElement, {
          text: function () { return text },
          action: function () { return 'copy' },
          container: typeof container === 'object' ? container : document.body
        })
        clipboard.on('success', function (e) {
          clipboard.destroy()
          resolve(e)
        })
        clipboard.on('error', function (e) {
          clipboard.destroy()
          reject(e)
        })
        document.body.appendChild(fakeElement);
        fakeElement.click();
        document.body.removeChild(fakeElement);
      })

[Inndy]

Fixed in v0.3.0