title: ReferenceError: "Swal is not defined"
body: <p>I'm working on small project using codeigniter and VueJs and sweet alert javascript library. but i get an error in my console <code>ReferenceError: "Swal is not defined"</code> once i call <code>swall.fire({})</code> inside my VueJs methods. 
  <strong>This is my code :</strong> </p>
  
  <pre><code>deleteCustomers(customer_id){
          Swal.fire({
             title: 'Are you sure?',
             text: "You won't be able to revert this!",
             icon: 'warning',
             showCancelButton: true,
             confirmButtonColor: '#3085d6',
             cancelButtonColor: '#d33',
             confirmButtonText: 'Yes, delete it!'
             }).then((result) =&gt; {
                axios.post('/Thirdparty/deleteCustomers', {id : customer_id}).then(function(response){
                   console.log(response.data);
                   //alert(response.data.error);
                   Swal.fire(
                   'Deleted!',
                   'Your file has been deleted.',
                   'success'
                   );
                });
             });
       }
  </code></pre>
  
  <p>and of course i have already imported swall using : <code>import Swal from 'sweetalert2';</code></p>
  
  <p><strong>NB</strong> : swall.fire doesn't work only inside Vuejs methods</p>