Making sure we print error messages more informatively

Signed-off-by: Alex Schlessinger <a.schlessinger@modcloth.com>
Reinstating the native dir-copying (over `cp -R`) after fixing the issue

Signed-off-by: Alex Schlessinger <a.schlessinger@modcloth.com>
Fixing file copy issue (fixes https://github.com/modcloth/bob/issues/18)

Signed-off-by: Alex Schlessinger <a.schlessinger@modcloth.com>