update user logup and login test
Add byebug to Gemfile. Add json parser assert to integration test.
add test document do define actions we shoule have and how we test them.
finish the group search action
Merge branch 'dev' into hbzhou

Conflicts:
	app/controllers/sessions_controller.rb
redefine the api for group action
set the limit route of checkouts and rewrite the checkout logic
add api doc
add group_info return after user signin
add api document came up with descussion with Hongbin
enhance the user login management
Merge branch 'dev' into hbzhou

Conflicts:
	app/controllers/sessions_controller.rb
fix routes error.
fix routes error.
fix the missing route issue
create user session test file. update test_arch doc.
finish group create action
Merge branch 'dev' of https://github.com/us4us/seed into dev
finish the group search action
update the api doc since 'message' fild is needed