update lesspass to version 6

package.json

@@ -29,7 +29,7 @@
     "font-awesome": "^4.7.0",
     "hint.css": "^2.4.1",
     "jwt-decode": "^2.1.0",
-    "lesspass": "^6.0.0-beta.6",
+    "lesspass": "^6.0.0",
     "lodash.debounce": "^4.0.8",
     "nock": "^9.0.2",
     "primer-css": "^4.3.0",