Include a way to require more than one reviewer for a pull-request

Currently, my team requires two 'approved' reviews to allow a PR to be merged, but there's no way to enforce it on Github. I'd like to request the ability to restrict merges of PRs without a user-defined number of 'approved' reviews.

No files, tests, or entry points are named. Start by locating the pull-request and review API surface in this JavaScript GitHub wrapper, then establish how the requested user-defined approval count fits the project. Done would require a defined implementation scope and tests for restricting merges based on multiple approved reviews.

Written by the indexing model from the issue text.