* Delete maprule. Fix Buildifier lint errors. Delete maprule and its tests: I wrote this rule, and I no longer plan to release it. Alternative rules exist that serve users' needs better. Fix also Buildifier lint errors that were making BuildKite red: https://buildkite.com/bazel/bazel-skylib/builds/659#ab98ac31-6e1c-415e-b8a8-5f8868340c7d
This rule is an alternative for genrule(): it can run a binary with the desired arguments, environment, inputs, and outputs, as a single build action, without shelling out to Bash. Fixes https://github.com/bazelbuild/bazel-skylib/issues/149