Having multiple drainpipe-dev folders in vendor directory is confusing

[mrdavidburns]

When adding drainpipe to a project via composer it contains a version of drainpipe-dev. This is confusing because when you add lullabot/drainpipe-dev to a project you have another copy of these files inside vendor/drainpipe-dev

[deviantintegral]

I think there's likely a way we can ignore the drainpipe-dev subdirectory when publishing drainpipe to packagist.

[davereid]

This actually wasn't fixed correctly. I validated that the drainpipe-dev folder is still present in the latest release download.