composer require git repository

composer.json

{
  "name": "my_vendor_name/my_package",
  "description": "My Package Description",
  "license": "GPL-3.0",
  "autoload": {
    "classmap": [ // search these directories for classes 
      "lib/"
    ]
  },
  "repositories": {
    "php-console-color": { // pseudonym of git repo
      "type": "package",
      "package": {
        "name": "coryjthompson/php-console-color",  // name of git repo
        "version": "1.0",
        "source": {
          "url": "https://github.com/coryjthompson/php-console-color.git", // url to repo
          "type": "git", // vcs or git
          "reference": "origin/master"
        }
      }
    }
  },
  "require": {
    "coryjthompson/php-console-color":"1.0" 
  }
}