init project

app/models/pull_request.rb

@@ -0,0 +1,10 @@
+class PullRequest < ApplicationRecord
+  #status 0 默认未合并， 1表示合并, 2表示请求拒绝
+  belongs_to :issue
+  belongs_to :user
+  belongs_to :project, :counter_cache => true
+  has_many :pull_request_assigns, foreign_key: :pull_request_id
+  has_many :pull_request_tags, foreign_key: :pull_request_id
+  has_many :project_trends, as: :trend, dependent: :destroy
+  has_many :attachments, as: :container, dependent: :destroy
+end