Update version number for Xenial prep guide, make years explicit

(This doc uses manual version numbers as it is linked to as `latest`
for ease of updating)

docs/upgrade/xenial_prep.rst

@@ -1,8 +1,8 @@
 Ubuntu 16.04 LTS (Xenial) migration - Preparatory steps
 =======================================================
-On 30 April 2019, Ubuntu 14.04 LTS (Trusty) will reach End of Life. After this date, no new security updates to the base operating system will be provided. It is therefore of critical importance for the security of all SecureDrop instances to upgrade to Ubuntu 16.04 LTS (Xenial) before April 30.
+On 30 April 2019, Ubuntu 14.04 LTS (Trusty) will reach End of Life. After this date, no new security updates to the base operating system will be provided. It is therefore of critical importance for the security of all SecureDrop instances to upgrade to Ubuntu 16.04 LTS (Xenial) before April 30, 2019.
 
-SecureDrop servers provisioned before February 26 use Ubuntu 14.04 LTS as the base operating system. Support for Ubuntu 16.04 LTS (which will receive security updates until April 2021) is scheduled to be included with the next release of SecureDrop, version 0.12.0, on February 26. The operating system update itself must be performed manually.
+SecureDrop servers provisioned before February 26, 2019 use Ubuntu 14.04 LTS as the base operating system. Support for Ubuntu 16.04 LTS (which will receive security updates until April 2021) is included with SecureDrop 0.12.0, released on February 26. The operating system update itself must be performed manually.
 
 We recommend that you plan two working days (after your instance has been updated to SecureDrop 0.12.0) to backup your instance, perform the upgrade, and test your instance once it is upgraded. We recommend scheduling this maintenance window no earlier than March 6.
 
@@ -34,7 +34,7 @@ If you have already confirmed that you have :ref:`SSH access <verify_ssh_access>
  apt-cache policy securedrop-app-code
 
 
-SecureDrop servers are updated automatically with the latest release version (0.11.1 as of January 24, 2019). Recently, some long-running SecureDrop instances were affected by a bug which will cause any updates after 0.10.0 to fail. If your instance is still running 0.10.0, please `consult our advisory <https://securedrop.org/news/advisory-automatic-update-failure-version-0100-0110-some-securedrop-instances/>`_ to update to the latest version.
+SecureDrop servers are updated automatically with the latest release version (0.12.0 as of February 26, 2019). Recently, some long-running SecureDrop instances were affected by a bug which will cause any updates after 0.10.0 to fail. If your instance is still running 0.10.0, please `consult our advisory <https://securedrop.org/news/advisory-automatic-update-failure-version-0100-0110-some-securedrop-instances/>`_ to update to the latest version.
 
 .. important::
  If your instance is affected by this bug, it will no longer receive automatic updates. This is a major security risk and we urge you to take manual action as soon as possible to update SecureDrop. Please do not hesitate to :ref:`contact us <contact_us>` if we can help.
@@ -62,7 +62,7 @@ The output from ``git status`` should include the following text:
 
 where ``<version>`` is  the version of the workstation code that is installed.
 
-If the *Admin Workstation* is at version 0.11.1, it is up-to-date, and you can proceed with :ref:`making a backup of the instance <backup_instance>` and :ref:`verifying SSH connectivity <verify_ssh_access>`. If the *Admin Workstation* is running an earlier version, you will need to upgrade it, using the appropriate steps for your version:
+If the *Admin Workstation* is at version 0.12.0, it is up-to-date, and you can proceed with :ref:`making a backup of the instance <backup_instance>` and :ref:`verifying SSH connectivity <verify_ssh_access>`. If the *Admin Workstation* is running an earlier version, you will need to upgrade it, using the appropriate steps for your version:
 
  - 0.9.1 to 0.10.0: `Upgrading from version 0.9.1 or later`_.
  - 0.4 to 0.9.0: `Upgrading from versions 0.4-0.9.0`_.
@@ -71,13 +71,13 @@ If the *Admin Workstation* is at version 0.11.1, it is up-to-date, and you can p
 Upgrading from version 0.9.1 or later
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-If the workstation is at least at version 0.9.1 and up to version 0.10.0, you should see a graphical updater informing you about the availability of a new version. The graphical updater looks like this:
+If the workstation is at least at version 0.9.1 and up to version 0.12.0, you should see a graphical updater informing you about the availability of a new version. The graphical updater looks like this:
 
 .. image:: ../images/0.6.x_to_0.7/securedrop-updater.png                        
 
 Follow the graphical prompts to complete the update. If you don’t see the graphical updater, make sure that you start up the *Admin Workstation* with both an Administration password set and the persistent volume unlocked.
 
-If you still can’t see the graphical prompt, then you can update manually by following the instructions for :ref:`upgrading from versions 0.4 to 0.9.0 <upgrade_04x>`. 
+If you still can’t see the graphical prompt, then you can update manually by following the instructions for :ref:`upgrading from versions 0.4 to 0.9.0 <upgrade_04x>`.
 
 .. _upgrade_04x:
 
@@ -91,7 +91,7 @@ If your workstation code version is between 0.4 and 0.9.0, then you will need to
   cd ~/Persistent/securedrop
   git fetch --tags
   gpg --recv-key "2224 5C81 E3BA EB41 38B3 6061 310F 5612 00F4 AD77"
-  git tag -v 0.11.1
+  git tag -v 0.12.0
 
 The output should include the following two lines:
 
@@ -104,10 +104,10 @@ Please verify that each character of the fingerprint above matches what is on th
 
 .. code:: sh
 
-  git checkout 0.11.1
+  git checkout 0.12.0
 
 .. important::
-  If you see the warning ``refname ‘0.11.1’ is ambiguous`` in the output, we recommend that you contact us immediately at [email protected] (GPG encrypted).
+  If you see the warning ``refname ‘0.12.0’ is ambiguous`` in the output, we recommend that you contact us immediately at [email protected] (GPG encrypted).
 
 Finally, run the following commands:
 
@@ -137,7 +137,7 @@ Open a terminal and run the following commands to install the SecureDrop app cod
   cd ~/Persistent
   git clone https://github.com/freedomofpress/securedrop.git
   cd ~Persistent/securedrop
-  git tag -v 0.11.1
+  git tag -v 0.12.0
 
 .. note:: 
   The SecureDrop application code must be installed in the `~/Persistent/securedrop` directory in order to complete the reprovisioning process successfully. Do not install it in a different location.
@@ -156,7 +156,7 @@ Now, check out the current release with the following command:
 
 .. code:: sh
   
-  git checkout 0.11.1
+  git checkout 0.12.0
 
 Next, mount the persistent volume of the old *Admin Workstation* in order to retrieve instance-specific files that you’ll need to set up the new workstation. To do so: