Request to submit XGBoost 1.0.0 to Homebrew (Homebrew/homebrew-core#50467) is still ongoing. In the meanwhile, we should create a Homebrew tap so that Mac users can install XGBoost easily.

Example:

# Load recipe xgboost.rb from GitHub repo hcho3/homebrew-repo
brew install hcho3/repo/xgboost
brew install hcho3/repo/py-xgboost  # Install Python package

cc @ankane