chore(build): upgrate to node 12 and gulp 4

package.json

@@ -31,7 +31,7 @@
     "@types/fs-extra": "^8.0.0",
     "@types/jest": "^24.0.15",
     "@types/lodash": "^4.14.136",
-    "@types/node": "^10.14.12",
+    "@types/node": "^12.6.2",
     "@types/rimraf": "^2.0.2",
     "@types/webpack": "^4.4.34",
     "ajv": "^6.10.1",
@@ -41,7 +41,7 @@
     "dgeni": "^0.4.12",
     "dgeni-packages": "0.16.10",
     "fs-extra": "^8.1.0",
-    "gulp": "3.9.1",
+    "gulp": "^4.0.2",
     "gulp-rename": "^1.4.0",
     "gulp-replace": "^1.0.0",
     "gulp-tslint": "^8.1.4",