Shell "bash" is not executable: No such file or directory on mac os

[kindermax]

having example command:

shell: bash
commands:
  push:
    cmd: git push origin master

will give us an error on macOS

Shell "bash" is not executable: No such file or directory
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
failed to run command 'publish': exit status 128

[kindermax]

fixed by #253