The main purpose of adding this (aside from simply implementing the full
GitHub API) is to establish the basic Commit type, so that we can build
around it for things like Events (see #4) and WebHooks (see #20).
- complete the rename from TreesService to GitService. For example,
renaming Get to GetTree, and Create to CreateTree.
- rename GitTree to TreeEntry. I really have no idea why GitHub chose
to use the field name "tree" for this, since these aren't necessarily
trees in the git sense. Looking at it more closely, these are really
just the entries within a tree, hence the rename.
- simplify several tests and shuffle some things for consistency with
the rest of the library
Oleksandr Redko