Copy the whole folder to to a subfolder on your project and add a reference to in in your package composer.json. I had to do this with jasonlewis/resource-watcher, so this is now my package autoload section:
"autoload": {
"psr-4": {
"PragmaRX\\Ci\\": "src/"
},
"psr-0": {
"JasonLewis\\ResourceWatcher": "src/Support/jasonlewis/resource-watcher/src"
}
},
As soon as it releases a composer.json compatible with Laravel 5 I just have to remove it from autoload and add the package to the require section, no need to change a single line of code.