Inconsistent 'type' field returned on S3 provider when calling .info()

[grantcopley]

When calling .info() on the Local or RAM provider, you are returned a 'type' which indicates if the path is a file or a directory.

var info = disk.info( "some_file.txt" );
expect( info.type ).toBe( "file" );

On the S3 provider though this fails because it is instead returning the Content-Type of the file, which in this case would be 'text/plain'.

Calling .info() should return consistent values for all providers.