Adding return type
Fixing URL combination
Fixing tests
Removing ResourceIterator in favor of FlatMapIterator

Adding a FlatMapIterator that is now used to iterate over a flattened
sequence of results after applying a JMESPath expression to a paginated
iterator.
make coverage now supports the TEST param like make test
Include ObjectURL in the result for CopyObject.
Fixing S3's Signature Version 4 pre-signed URL implementation to use the correct payload when signing.
Adding .gitattributes to trim down the dist