message: fix table alignment
diff: <thead>
  <tr>
  <th class="mdl-data-table__cell--non-numeric">{{ 'NAME' | translate}}</th>
  - <th>{{ 'DATE' | translate }}</th>
  - <th>{{ 'ACTIONS' | translate }}</th>
  + <th class="mdl-data-table__cell--non-numeric">{{ 'DATE' | translate }}</th>
  + <th class="mdl-data-table__cell--non-numeric">{{ 'ACTIONS' | translate }}</th>
  </tr>
  </thead>
  <tbody>
  <tr *ngFor="let snapshot of volume.snapshots">
  <td class="snapshot-name mdl-data-table__cell--non-numeric">{{ snapshot.name }}</td>
  - <td>{{ snapshot.created | date:'medium' }}</td>
  - <td>
  + <td class="mdl-data-table__cell--non-numeric">{{ snapshot.created | date:'medium' }}</td>
  + <td class="mdl-data-table__cell--non-numeric">
  <button
  *ngFor="let action of snapshotActionsService.Actions"
  class="button-18px snapshot-button"
  