Use Gitlab::PushOptions for `ci.skip` push option

Previously the raw push option Array was sent to Pipeline::Chain::Skip.

This commit updates this class (and the chain of classes that pass the
push option parameters from the API internal `post_receive` endpoint to
that class) to treat push options as a Hash of options parsed by
GitLab::PushOptions.

The GitLab::PushOptions class takes options like this:

    -o ci.skip -o merge_request.create -o merge_request.target=branch

and turns them into a Hash like this:

    {
      ci: {
        skip: true
      },
      merge_request: {
        create: true,
        target: 'branch'
      }
    }

This now how Pipeline::Chain::Skip is determining if the `ci.skip` push
option was used.

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/gitlab/push_options.rb b/lib/gitlab/push_options.rb
index 923aa09527d..7c655c12995 100644
--- a/lib/gitlab/push_options.rb
+++ b/lib/gitlab/push_options.rb
@@ -27,6 +27,11 @@ module Gitlab
       options.dig(*args)
     end
 
+    # Allow #to_json serialization
+    def as_json(*_args)
+      options
+    end
+
     private
 
     def parse_options(raw_options)