Remove extraneous leading forward slash on uploaded files

[ahlec]

There's a separate PR here (#8) which does the same thing, but looks to be based off an older version of the repo.

I found when I was using this locally that if I wanted to upload files to the root of the S3 bucket, I wasn't able to -- it would always upload it to a directory that existed in the root, named /. So the file foo.txt that I wanted in the root was being uploaded inside of directory /.

This seems to be the case when you have an empty uploadPath. The filepath (pre-upload path) still has the leading / from lopping off the base, which is useful for joining the uploadPath to it and producing a valid directory structure. But when there is no uploadPath, it still keeps the separator, which throws off the process.

[adrianfalleiro]

Thanks I'll take a look.

[pascencio]

@adrianfalleiro I have same problem here. Thanks in the advance!