[GulpV1] Migrated to Node10 (microsoft#14195)

Co-authored-by: Anatoly Bolshakov <anatoly.bolshakov@akvelon.com>

Author: Sergey Dobrodeev

Tasks/GulpV1/Tests/L0.ts

@@ -9,7 +9,7 @@ describe('GulpV1 Suite', function () {
     after(() => {
     });
 
-    it('Does a basic hello world test', function(done: MochaDone) {
+    it('Does a basic hello world test', function(done: Mocha.Done) {
         // TODO - add real tests
         done();
     });

Tasks/GulpV1/Tests/package.json

@@ -17,6 +17,6 @@
   },
   "homepage": "https://github.com/Microsoft/azure-pipelines-tasks#readme",
   "devDependencies": {
-    "@types/mocha": "^5.2.0"
+    "@types/mocha": "^5.2.7"
   }
 }