Bug 1535011: update `versioncontrol.rst` r=dustin

Small updates to the version control documents regarding
upgrading `robustcheckout.py`. I noticed that we still
reference `build-puppet` from it's former home on hgmo
and don't include OpenCloudConfig in our list of places
we need to vendor `robustcheckout` changes.

Differential Revision: https://phabricator.services.mozilla.com/D23742

--HG--
extra : moz-landing-system : lando

taskcluster/docs/versioncontrol.rst

@@ -28,6 +28,7 @@ The locations are as follows:
 - In-tree: ``testing/mozharness/external_tools/robustcheckout.py``
 - Treescript: ``https://github.com/mozilla-releng/treescript/tree/master/treescript/py2/robustcheckout.py``
 - build-puppet: ``https://github.com/mozilla-releng/build-puppet/blob/master/modules/mercurial/files/robustcheckout.py``
+- OpenCloudConfig: ``https://github.com/mozilla-releng/OpenCloudConfig/blob/master/userdata/Configuration/FirefoxBuildResources/robustcheckout.py``
 
 
 Debian Packages for Debian Based Docker Images
@@ -93,7 +94,7 @@ Puppet Maintained Hosts
 Some hosts (namely macOS machines) are managed by Puppet and Puppet is used
 to install Mercurial.
 
-Puppet code lives in the https://hg.mozilla.org/build/puppet repository.
+Puppet code lives in the https://github.com/mozilla-releng/build-puppet repository.
 Relevant files are in ``modules/mercurial/``,
 ``modules/packages/manifests/mozilla/mozilla-python27-mercurial-debian/``,
 and ``modules/packages/manifests/mozilla/py27_mercurial*``. A copy of