Set users home dir to /app.

This works best with npm install as user when run in a dev environment.

docker/dockerfiles/base

@@ -6,7 +6,7 @@ ENV LANG=C.UTF-8
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
 
-RUN groupadd --gid 1000 kitsune && useradd -g kitsune --uid 1000 --shell /usr/sbin/nologin kitsune
+RUN useradd  -d /app -M --uid 1000 --shell /usr/sbin/nologin kitsune
 
 # Node is used in the staticfiles dockerfile but since this base image
 # is used for development get it installed here too.