Merge branch 'gitlab-workhorse-1.0.0' into 'master'

Update GitLab Workhorse to v1.0.0, improving error handling

This is an update to v1.0.0 - which does not signify any breaking changes, but is merely in accordance with http://semver.org/#how-do-i-know-when-to-release-100

See merge request !7289

GITLAB_WORKHORSE_VERSION

-0.8.5
+1.0.0

doc/install/installation.md

@@ -403,7 +403,7 @@ If you are not using Linux you may have to run `gmake` instead of
     cd /home/git
     sudo -u git -H git clone https://gitlab.com/gitlab-org/gitlab-workhorse.git
     cd gitlab-workhorse
-    sudo -u git -H git checkout v0.8.5
+    sudo -u git -H git checkout v1.0.0
     sudo -u git -H make
 
 ### Initialize Database and Activate Advanced Features

doc/update/8.13-to-8.14.md

@@ -84,7 +84,7 @@ GitLab 8.1.
 ```bash
 cd /home/git/gitlab-workhorse
 sudo -u git -H git fetch --all
-sudo -u git -H git checkout v0.8.5
+sudo -u git -H git checkout v1.0.0
 sudo -u git -H make
 ```