docs-test: Fix documentation links.

- Fix internal documentation links and anchors according last project documentation version.

Fixes #1492

README.md

@@ -110,7 +110,7 @@ contributing!
 [cla]: https://opensource.dropbox.com/cla/
 [dev-install]: https://zulip.readthedocs.io/en/latest/dev-overview.html
 [doc]: https://zulip.readthedocs.io/
-[doc-commit-style]: http://zulip.readthedocs.io/en/latest/code-style.html#commit-messages
+[doc-commit-style]: http://zulip.readthedocs.io/en/latest/version-control.html#commit-messages
 [doc-dirstruct]: http://zulip.readthedocs.io/en/latest/directory-structure.html
 [doc-newfeat]: http://zulip.readthedocs.io/en/latest/new-feature-tutorial.html
 [doc-test]: http://zulip.readthedocs.io/en/latest/testing.html

docs/architecture-overview.md

@@ -135,7 +135,7 @@ from outside.
     sent to the Tornado server. These are requests to the real-time push
     system, because the user's web browser sets up a long-lived TCP
     connection with Tornado to serve as [a channel for push
-    notifications](https://en.wikipedia.org/wiki/Push_technology#Long_Polling).
+    notifications](https://en.wikipedia.org/wiki/Push_technology#Long_polling).
     nginx gets the hostname for the Tornado server via
     `puppet/zulip/files/nginx/zulip-include-frontend/upstreams`.
 -   Requests to all other paths are sent to the Django app via the UNIX

docs/dev-env-first-time-contributors.md

@@ -129,7 +129,7 @@ Installed the plugin 'vagrant-lxc (1.2.1)'!
 ```
 
 If you encounter an error when trying to install the vagrant-lxc plugin, [see
-this](#nomethoderror-when-installing-vagrant-lxc-plugin-ubuntu-1604).
+this](#nomethoderror-when-installing-vagrant-lxc-plugin-ubuntu-16-04).
 
 ##### 4. Configure sudo to be passwordless
 

docs/prod-install.md

@@ -74,7 +74,7 @@ These settings include:
   mechanism by uncommenting its corresponding line, and then also do
   any additional configuration required for that backend as documented
   in the `settings.py` file.  See the [section on
-  Authentication](prod-auth-first-login.html) for more detail on the
+  Authentication](prod-authentication-methods.html) for more detail on the
   available authentication backends and how to configure them.
 
 - `EMAIL_*`, `DEFAULT_FROM_EMAIL`, and `NOREPLY_EMAIL_ADDRESS`:

docs/prod-maintain-secure-upgrade.md

@@ -24,7 +24,7 @@ You also have the option of creating your own release tarballs from a
 copy of the zulip.git repository using
 `tools/build-release-tarball`. And, starting with Zulip version 1.4,
 you can upgrade Zulip [to a version in a Git repository
-directly](#upgrade-from-a-git-repository).
+directly](#upgrading-from-a-git-repository).
 
 Next, run as root: