add a Login button to the header

src/components/layout/TheHeader.vue

@@ -6,14 +6,27 @@
         <li>
           <router-link to="/coaches">All Coaches</router-link>
         </li>
-        <li>
+        <li v-if="isLoggedIn">
           <router-link to="/requests">Requests</router-link>
         </li>
+        <li v-else>
+          <router-link to="/auth">Login</router-link>
+        </li>
       </ul>
     </nav>
   </header>
 </template>
 
+<script>
+export default {
+  computed: {
+    isLogggedIn() {
+      return this.$store.getters.isAuthenticated;
+    }
+  }
+};
+</script>
+
 <style scoped>
 header {
   width: 100%;