Add export-ignore option to reduce the archive size of composer downloading.
Add export-ignore option to reduce the archive size of composer downloading.

UFOMelkor/PhpMetrics,phpmetrics/PhpMetrics,phpmetrics/PhpMetrics,Halleck45/PhpMetrics,UFOMelkor/PhpMetrics,UFOMelkor/PhpMetrics,phpmetrics/PhpMetrics,Halleck45/PhpMetrics