@spec merge(Tentacat.Client.t(), binary(), binary(), binary(), binary(), binary()) ::
  Tentacat.response()

Merge a branch into another.

You can use both branch names and/or a commit SHA1. When the commit message is empty, Github will apply the default commit message.

Example

Tentacat.Repositories.Merges.merge client, "elixir-lang", "elixir", "master", "123-another-feature", ""
Tentacat.Repositories.Merges.merge client, "elixir-lang", "elixir", "master", "123-another-feature", "not the default commit_message"
Tentacat.Repositories.Merges.merge client, "elixir-lang", "elixir", "8e50d79f2ba0d665b9966908cbf22c6f463228d6", "bafdae8b93e74738c12515c14c7cf9acc652650a", ""

More info at: https://developer.github.com/v3/repos/merging/#perform-a-merge