Update dependency pug to ^2.0.4 (#711)

| datasource | package | from          | to    |
| ---------- | ------- | ------------- | ----- |
| npm        | pug     | 2.0.0-beta.12 | 2.0.4 |

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

example/zoo/package.json

@@ -12,7 +12,7 @@
     "express-basic-auth": "^1.2.1",
     "lightstep-tracer": "^0.34.0",
     "opentracing": "0.14.7",
-    "pug": "^2.0.0-beta.12",
+    "pug": "^2.0.4",
     "request": "^2.88.2",
     "restler": "^3.4.0",
     "sharp": "^0.33.5",