Remove CentOS 6 tests (#1139)

docs/CONTROLLER.md

@@ -69,42 +69,3 @@ The behaviour of this controller can be customized through the following environ
 
 This controller is useful when you want to debug Jenkins while you run a test. It can be also used during
 iterative test development to execute tests quickly.
-
-## Vagrant family of controllers
-There's a family of controllers which use Vagrant to launch a virtual machine and then launch jenkins.war inside.
-
-When run for the first time, this test harness will create a virtual machine.
-To make repeated tests fast, the VM won't get shut down automatically at the end of a run.
-
-To do shut it down, cd `vagrant/*` and run `vagrant halt`. You can run any other Vagrant commands
-in this manner, which is useful for debugging.
-
-You can also create `pre-configure.sh` and/or `post-configure.sh` in the current directory as needed
-to customize how the Vagrant VM is initialized. These scripts are copied into the VM and then executed:
-
-* `pre-configure.sh` runs before the controller attempts to install Jenkins
-* `post-configure.sh` runs after the controller finished installing Jenkins
-
-### Ubuntu controller (TYPE=ubuntu)
-This controller uses Vagrant to run Ubuntu, then deploy Jenkins from an APT repository as a debian package.
-(This controller is not yet capable of testing an individual `*.deb` file.)
-
-Variables:
-
-* `REPO_URL` The location of APT repository in the format used by `/etc/apt/sources.list`, such as `http://pkg.jenkins-ci.org/debian binary/`
-
-### CentOS controller (TYPE=centos)
-This controller uses Vagrant to run CentOS, then deploy Jenkins from an RPM repository.
-(This controller is not yet capable of testing an individual `*.rpm` file.)
-
-Variables:
-
-* `REPO_URL` The location of RPM repository, such as `http://pkg.jenkins-ci.org/opensuse/`
-
-### OpenSUSE controller (TYPE=opensuse)
-This controller uses Vagrant to run CentOS, then deploy Jenkins from an RPM repository.
-(This controller is not yet capable of testing an individual `*.rpm` file.)
-
-Variables:
-
-* `REPO_URL` The location of RPM repository, such as `http://pkg.jenkins-ci.org/opensuse/`