Why is Github asking for username/password when following the instructions on screen and pushing a new repo?

Don't use HTTP use SSH instead

change

https://github.com/WEMP/project-slideshow.git 

to

[email protected]:WEMP/project-slideshow.git

you can do it in .git/config file

I had this same issue and wondered why it didn't happen with a bitbucket repo that was cloned with https. Looking into it a bit I found that the config for the BB repo had a URL that included my username. So I manually edited the config for my GH repo like so and voila, no more username prompt. I'm on Windows.

Edit your_repo_dir/.git/config (remember: .git folder is hidden)

Change:

https://github.com/WEMP/project-slideshow.git

to:

https://*username*@github.com/WEMP/project-slideshow.git

Save the file. Do a git pull to test it.

The proper way to do this is probably by using git bash commands to edit the setting, but editing the file directly didn't seem to be a problem.

Here is an official answer to this:

If Git prompts you for a username and password every time you try to interact with GitHub, you're probably using the HTTPS clone URL for your repository.

Using an HTTPS remote URL has some advantages: it's easier to set up than SSH, and usually works through strict firewalls and proxies. However, it also prompts you to enter your GitHub credentials every time you pull or push a repository.

You can configure Git to store your password for you. If you'd like to set that up, read all about setting up password caching.