Add first version of "block skip checks" hook

[steffen]

This hook disallows skipping status checks.

It's basically disabling this feature:
https://help.github.com/articles/about-status-checks/#skipping-and-requesting-checks-for-individual-commits

[larsxschneider]

I think this call would fail if you push a new branch as $OLDREV is 40 zeros in that case. See https://github.com/github/platform-samples/blob/master/pre-receive-hooks/block_confidentials.sh#L38

[jonico]

I would also wonder whether you like to recheck all commits again if somebody was copying a branch and pushing it again with a new commit on top, have a look at https://github.com/github/platform-samples/blob/master/pre-receive-hooks/block_unsigned_commits.sh#L15-L42 for an example how to exclude commits already in the repo

[stoe]

This looks promising.
Only thing it doesn’t handle is pushes that create a new branch, zero sha.