Create a new repository

To initialize the branches on the Github repository, locally run the following commands:

export REPO=name_of_the_repo
mkdir $REPO
cd $REPO
git init

Then, for each branch run:

export BRANCH=8.0
git checkout -b $BRANCH

Create README, .travis.yml, .gitignore... using https://github.com/OCA/maintainer-quality-tools/tree/master/sample_files as a starting point

git add . 
git commit
git remote add origin git@github.com:OCA/$REPO
git push origin $BRANCH:$BRANCH