Add new pre-receive and post-receive hooks

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

hooks/post-receive

+#!/usr/bin/env ruby
+
+# This file was placed here by GitLab. It makes sure that your pushed commits
+# will be processed properly.
+# You can add your own hooks to this file, but be careful when updating gitlab-shell!
+
+changes = ARGF.read
+key_id  = ENV['GL_ID']
+repo_path = Dir.pwd
+
+require_relative '../lib/gitlab_post_receive'
+
+if GitlabPostReceive.new(repo_path, key_id, changes).exec
+  exit 0
+else
+  exit 1
+end

hooks/pre-receive

+#!/usr/bin/env ruby
+
+# This file was placed here by GitLab. It makes sure that your pushed commits
+# will be processed properly.
+# You can add your own hooks to this file, but be careful when updating gitlab-shell!
+
+refs = ARGF.read
+key_id  = ENV['GL_ID']
+repo_path = Dir.pwd
+
+require_relative '../lib/gitlab_access'
+
+if GitlabAccess.new(repo_path, key_id, refs).exec
+  exit 0
+else
+  exit 1
+end