Expand to export basic glob

[golmansax]

Hi, I like the buildpack, but my use case is to delete source maps after they get created in the build step so I need basic glob functionality.

One idea is to do something like find . -name "${GLOB}" | xargs rm. I'm happy to submit a pull request if you think this is a good route. Thanks!

[BuonOmo]

This would be a good route if it comes with tests I guess:

I might expand it to support file globs, but for the moment it's not necessary and the testing implications give me the willies.

Another implementation idea would be to just ls ${GLOB} | xargs rm -rf. I'm not sure find is necessary (-rf is here for folders).