From code.gitea.io/go-sdk/gitea
  To code.gitea.io/sdk/gitea

- Update import paths from github.com/go-gitea to code.gitea.io
- Fix import path for travis

See https://docs.travis-ci.com/user/languages/go#Go-Import-Path

* Write LDAP, SMTP, PAM, DLDAP back to all uppercase

* Fix type in unused constant name

* Other MixCased fixes

* Complete MixerCasing of template constants

* Re uppercase LTS and LDAPS suffixes

* Uppercase JSON suffix in constant names

* Proper case LoginNoType

* Prefix unexported template path constants with "tpl"

See https://github.com/golang/go/wiki/CodeReviewComments#mixed-caps

- Refactor code to use sync.UniqueQueue
- Closes #3509

Unix() already uses UTC as timezone

This prevents user retrieve arbitrary webhook by changing URL to
access webhook from other unauthorized repositories.

When repository contains a Slack type hook,
it changes original payload content.

This patch fixes it by using a local object to store
newly created Slack payload instead of assigning
back to the same variable.