You have created a new package.
When you build egg in order to distribute ir you have always an dev in the name of tar.gz of file and you don’t understand.
In your setup.py , your egg version is good (without dev word). You don’t know where this dev is provided.
Please , look to setup.cfg file. If there is those lines , you’re on the good way :
[egg_info] tag_build = dev
