download failure

[SvenDowideit]

svend_000@T440S /c/Program Files/Boot2Docker
$ ./boot2docker-cli.exe download
2014/04/09 10:29:12 Downloading boot2docker ISO image...
2014/04/09 10:29:13 Latest release is v0.8.0
2014/04/09 10:30:31 Failed to download ISO image: rename c:\Users\svend_000\.boo
t2docker\boot2docker.iso.download c:\Users\svend_000\.boot2docker\boot2docker.is
o: Cannot create a file when that file already exists.

[SvenDowideit]

and it works fine on linux - what a joy to debug this is

[gmlewis]

Yeah, we probably need to delete the file first before renaming.
Or maybe just copy instead of rename.

[riobard]

This one is a duplicate of #55