Update fs usages according to node v10 deprecations

lundibundi · tshemsedinov · commit fa3bc758a593 · 2018-07-29T00:09:07.000+03:00
As per this nodejs/node#12562 node PR callback in async fs functions is no longer optional. This commit fixes remaining usages in impress. Refs: #852 PR-URL: #856
diff --git a/lib/application.js b/lib/application.js
@@ -615,7 +615,8 @@ const mixin = (application) => {
         application.model[sectionName] = exports;
       } else if (placeName === 'setup') {
         api.fs.writeFile(
-          path + '/' + sectionName + '.done', new Date().toISOString()
+          path + '/' + sectionName + '.done', new Date().toISOString(),
+          api.common.emptiness
         );
       }
       callback();
