This turns the existing script into a proper sh_binary, and injects
dependencies (kubectl and jq) as deps into it.
This change also pulls in BUILDfiles for jq, and a dep (oniguruma) into
//third_party, and adds buildable external repositories for them.
The jq/oniguruma BUILDfiles are lifted from
https://github.com/attilaolah/bazel-tools/.
Change-Id: If2e548bd60a8fd34e4f3be767ae59c6b2f2286d9
