build(app): Fix deploy commands

app.py

@@ -6,6 +6,6 @@ subprocess.run("pwd && ls -al", shell=True)
 subprocess.run("export PORT=7860", shell=True)
 subprocess.run(["echo", '"PORT set to \$PORT"'])
 
-subprocess.run("npm install --prefix app", shell=True)
+subprocess.run("npm --prefix app install", shell=True)
 subprocess.run("npm run build --prefix app", shell=True)
 subprocess.run("node app/build", shell=True)