Add depth attribute to git resource

[tyamagu2]

It would be nice to have depth option supported when you clone a git repository with long history.

This patch adds depth attribute to git resource that uses depth option when cloning like the example below;

git "/tmp/git_repo_depth_1" do
  repository "https://github.com/ryotarai/infrataster.git"
  depth 1
end

# => git clone --depth 1 https://github.com/ryotarai/infrataster.git /tmp/git_repo_depth_1

[sorah]

Looks fine. @ryotarai 👓 ?

[ryotarai]

LGTM
Thank you 👍

[ryotarai]

released in v1.9.10