ui: build tweaks

- ignore ui/dist dir
- dev-start.sh prompts for npm instead of elm-app

.gitignore

@@ -46,6 +46,6 @@ _testmain.go
 # elm-repl generated files
 repl-temp-*
 # Distribution
-#/ui/build/
+/ui/dist/
 # Dependency directories
 /ui/node_modules

etc/dev-start.sh

@@ -26,7 +26,7 @@ fi
 index="$INBUCKET_WEB_UIDIR/index.html"
 if ! test -f "$index"; then
   echo "$index does not exist!" >&2
-  echo "Run 'elm-app build' from the 'ui' directory." >&2
+  echo "Run 'npm run build' from the 'ui' directory." >&2
   exit 1
 fi