Update `browserify` to v16.

package.json

@@ -21,7 +21,7 @@
     "babel-register": "^6.26.0",
     "babelify": "^8.0.0",
     "browser-sync": "^2.23.5",
-    "browserify": "^15.1.0",
+    "browserify": "^16.2.2",
     "chai": "^4.1.2",
     "chalk": "1.1.3",
     "cssnano": "^3.10.0",
@@ -69,7 +69,7 @@
     "typescript": "^2.8.1",
     "uppy-server": "^0.13.1",
     "verdaccio": "^3.2.0",
-    "watchify": "^3.9.0",
+    "watchify": "^3.11.0",
     "wdio-mocha-framework": "^0.5.12",
     "wdio-sauce-service": "^0.4.6",
     "wdio-static-server-service": "^1.0.1",