forked from rook/rook
Create a makefile (and shell) variable that can be used to invoke a different command line, such as 'sha256sum' instead of the default 'shasum -a 256'. The shasum tool is left as the default but, at least on fedora, this comes from a perl package and it may be that sha256sum, which comes from coreutils would allow building on a more minimal install. Signed-off-by: John Mulligan <jmulligan@redhat.com>