Merge pull request #2 from fengzifz/feature_register

Feature register
Merge pull request #3 from fengzifz/develop

Develop
Merge branch 'master' of github.com:fengzifz/bird
Display error code.
Merge pull request #4 from fengzifz/feature_register

Change the port from 3000 to 80.
Merge branch 'master' of github.com:fengzifz/bird
Add should and supertest module.
Add BDD unit test.
Add test cases.
Modify varriable name.
Add unit test for
Merge branch 'master' into feature_register