Resolve "Die Statistiken sollten auch in ElasticSearch hinterlegt werden."

Related to #384 (closed)

src/main/java/at/ac/uibk/gitsearch/web/rest/ReviewResource.java

@@ -125,6 +125,7 @@ public class ReviewResource {
      * @return the {@link ResponseEntity} with status {@code 200 (OK)} and the list of reviews in body.
      */
     @GetMapping("/review")
+    @PreAuthorize(ADMIN_ROLE)
     public ResponseEntity<List<ReviewDTO>> getAllReviews(ReviewCriteria criteria) {
         log.debug("REST request to get Reviews by criteria: {}", criteria);
         List<ReviewDTO> entityList = reviewQueryService.findByCriteria(criteria);