changes backslashes to forward slashes in relative path before upload…

[joeenzminger]

…ing.

I've run into an issue where backslashes (using vinyl-s3 on windows) don't display correctly the s3 interface (path is treated as a single file rather than a directory hierarchy).

I know internally S3 doesn't care, but this fix does make it easier to debug and visualize uploads to S3 using the AWS console.

[joeenzminger]

A little more info on this - on windows, file.relative returns backslashed paths, even though cwd, base, and path have forward slashes. S3 expects forward slash path names in the key. Backslashes are treated as string literals. Since vinyl-s3 uses file.relative unmodified, there isn't a way modify the key using a prior pipeline plugin (like gulp-slash).