Move app/javascript out of builder after unneeded

Dockerfile

@@ -34,7 +34,8 @@ RUN rails assets:precompile && \
       rm -rf tmp/cache log && \
       mkdir -p /var/cache/app/app && \
       mv node_modules spec /var/cache/app && \
-      mv app/assets /var/cache/app/app
+      mv app/assets /var/cache/app/app && \
+      mv app/javascript /var/cache/app/app
 
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 FROM base AS dev