Move the code that existed in tests/fetch.py for determining the path to
'git-make-shallow' into the git module and reference it.
This ensures that 'git-make-shallow' is always available and the desired
version regardless of the path variable or whether git exposes the
command.
(Bitbake rev: 6b508ab8fd5aa796c1c00c970e81e5e93f84d35d)
Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>