title: vuetify v-data-table not showing nested object data
body: <p>I have v-datatable using vuetify I want to get nested data to be displayed unfortunately I can't get the nested object value this is my code</p>
  
  <pre><code>&lt;template slot="items" slot-scope="props"&gt;
            &lt;tr @click="rowClick(props.item.name)"&gt;
              &lt;td
                class="text-xs-right"
              &gt;{{ props.item.firstName + props.item.middleName + props.item.lastName}}&lt;/td&gt;
              &lt;td class="text-xs-right"&gt;{{ props.item.gender }}&lt;/td&gt;
              &lt;td class="text-xs-right"&gt;{{ props.item.dateOfBirth }}&lt;/td&gt;
              &lt;td class="text-xs-right"&gt;{{ props.item }}&lt;/td&gt;
            &lt;/tr&gt;
          &lt;/template&gt;
  </code></pre>
  
  <p>and this is the header</p>
  
  <pre><code>  headers: [
      {
        text: "MCN",
        align: "left",
        sortable: false,
        value: "medicalRecordNumber",
        width: "16%"
      },
      { text: "Full Name", value: "fullName", width: "16%" },
      { text: "Gender", value: "gender", width: "16%" },
      { text: "Date Of Birth", value: "dateOfBirth", width: "16%" },
      { text: "Phone Number", value: "address", width: "16%" },
      { text: "Actions", value: "action", sortable: false }
    ],
  </code></pre>
  
  <p>and my data </p>
  
  <pre><code>{
              "medicalRecordNumber": "dsUlBnusoH",
              "fullName": "Rozella SchusterProf. Chloe Hauck DDSAthena Hill III",
              "firstName": "Rozella Schuster",
              "middleName": "Prof. Chloe Hauck DDS",
              "lastName": "Athena Hill III",
              "gender": "Female",
              "dateOfBirth": "2018-04-18",
              "language": "Tigregna",
              "religion": "Catholic",
              "address": {
                  "region": "Addis Ababa",
                  "woreda": "bole",
                  "kebele": "10",
                  "houseNumber": "35698",
                  "telPhoneNumber": null,
                  "mobilePhoneNumber": null
              },
              "emergencyContact": {
                  "firstName": "Krista Collins III",
                  "middleName": "Onie Roob",
                  "lastName": "Dr. Vivien Miller PhD",
                  "emergencyContactAddress": null
              }
          }
  </code></pre>
  
  <p>i got the values but not the nested one it displays     [object Object]</p>