Add Shell linter - Differential-ShellCheck (#1419)
Add Shell linter - Differential-ShellCheck (#1419)

Signed-off-by: Jan Macku <072e5c330a444479c692be236f9829f0dba620fe@redhat.com>
Co-authored-by: Mislav Marohnić <46f1a0bd5592a2f9244ca321b129902a06b53e03@mislav.net>
rbenv/rbenv,rbenv/rbenv