Please create default branch, master?

@pmatos Thank you for setting this up!

I cloned, added an initial commit to a local master branch, and tried to push. Git complained, providing this message from the GitLab remote:

Pushing to git@gitlab.com:racket-news/racket-survey-2019.git
Counting objects: 3, done.
Writing objects: 100% (3/3), 933 bytes | 933.00 KiB/s, done.
Total 3 (delta 0), reused 0 (delta 0)
remote: GitLab:         
remote: A default branch (e.g. master) does not yet exist for racket-news/racket-survey-2019        
remote: Ask a project Owner or Maintainer to create a default branch:        
remote: 
remote:   https://gitlab.com/racket-news/racket-survey-2019/-/project_members        
remote: 
To gitlab.com:racket-news/racket-survey-2019.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'git@gitlab.com:racket-news/racket-survey-2019.git'