Bump node from 12 to 19

Bumps node from 12 to 19.

Closes #175
---
updated-dependencies:
- dependency-name: node
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Change-Id: Ia72cbf2e85984aea8cb6703b7b889cc9f1069796
diff --git a/Dockerfile b/Dockerfile
index 51198cc..a03ca5e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,7 @@
 # Build assets in builder image
-FROM node:12 as assetbuilder
+FROM node:19 as assetbuilder
+
+WORKDIR '/app'
 
 # This follows the "multi-stage build" pattern