build: output directory for gulp tsconfig (#4186)

Author: devversion

tools/gulp/tsconfig.json

@@ -6,6 +6,7 @@
     "lib": ["es2015", "dom"],
     "module": "commonjs",
     "moduleResolution": "node",
+    "outDir": "../../dist/tools/gulp",
     "noEmitOnError": true,
     "noImplicitAny": true,
     "target": "es5",