003af5f0

By: Greg Pfeil <greg@technomadic.org>

Catch GitHub settings that need a paid plan

Private repositories on the “free” plan can’t use branch protection, wikis,
rulesets or environments, and Probot’s Settings app reports nothing when GitHub
turns one of them down. Worse, its request ordering means a single rejection can
take unrelated settings with it.

`services.github.plan` now records the owning account’s plan, so these cases can
be caught at build time.

Also swaps the `branches` and `labels` descriptions, which described each other.