Eliminate manual call to os.remove by using tempfile context manager.
The 'get bb env' script has to be created in a directory (rather than
using a NamedTemporaryFile directly, for instance), since otherwise
you'll get a "Text file busy" error when trying to execute the script.
Signed-off-by: Chris Laplante <chris.laplante@agilent.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>