Up until now you and I were kind of forced to generate a fly.toml as your configuration file during fly launch; this is neither in line with the way you might use fly deploy with different configurations or with a pleasant dx, so we’ve added the -c flag to fly launch
You can use it like so:
fly launch -c fly.dev.toml
This also interops with the yaml/json features:
fly launch -c fly.dev.json
Enjoy 
