In this example i used the original package php-edifact/edifact-generator and created a local checkout of the fork davidvandertuijn/edifact-generator for pushing changes, afterwards i've added the GitHub repository for production.
Original package
"require": {
"php-edifact/edifact-generator": "dev-master"
"
Development environment
git clone https://github.com/davidvandertuijn/edifact-generator.git vendor/davidvandertuijn/edifact-generator
"classmap": [
"vendor/davidvandertuijn/edifact-generator/src/Generator"
]
Production environment
"repositories": [{
"type": "vcs",
"url": "https://github.com/davidvandertuijn/edifact-generator"
}]
"require": {
"davidvandertuijn/edifact-generator": "dev-master"
}