disable close participation button when is closed

src/Bundle/ChillMainBundle/Resources/public/scss/chillmain.scss

@@ -39,8 +39,17 @@ div.subheader {
   height: 130px;
 }
 
-//// VUEJS ////
+//// SCRATCH BUTTONS
+.sc-button {
+   &.disabled {
+      cursor: default;
+      &.bt-remove {
+         background-color: #d9d9d9;
+      }
+   }
+}
 
+//// VUEJS ////
 div.vue-component {
   padding: 1.5em;
   margin: 2em 0;
@@ -146,7 +155,6 @@ div.results {
       }
    }
 }
-
 .discret {
    color: grey;
    margin-right: 1em;

src/Bundle/ChillPersonBundle/Resources/public/vuejs/AccompanyingCourse/components/PersonItem.vue

@@ -29,10 +29,12 @@
             </button>
          </li-->
          <li>
-            <button class="sc-button bt-remove"
+            <button v-if="!participation.endDate"
+               class="sc-button bt-remove"
                :title="$t('action.remove')" 
                @click.prevent="$emit('close', participation)">
             </button>
+            <button v-else class="sc-button bt-remove disabled"></button>
          </li>
       </ul>
    </td>