revert(kitchen+travis): disable debian-8 due to 2019.2 bug

This reverts commit 178c710.

Fix is to use `debian:jessie-backports`, to fix in the next commit.

.travis.yml

@@ -19,7 +19,7 @@ before_install:
 env:
   matrix:
     - INSTANCE: default-debian-9
-    # - INSTANCE: default-debian-8
+    - INSTANCE: default-debian-8
     - INSTANCE: default-ubuntu-1804
     - INSTANCE: default-ubuntu-1604
     - INSTANCE: default-centos-7

kitchen.yml

@@ -20,14 +20,11 @@ platforms:
       run_command: /lib/systemd/systemd
       provision_command:
         - apt-get update && apt-get install -y udev
-  # With the release of `2019.2`, `debian-8` is no longer working
-  # Disabling until the following upstream bug has been resolved:
-  #   * https://github.com/saltstack/salt/issues/51808
-  # - name: debian-8
-  #   driver_config:
-  #     run_command: /lib/systemd/systemd
-  #     provision_command:
-  #       - apt-get update && apt-get install -y udev
+  - name: debian-8
+    driver_config:
+      run_command: /lib/systemd/systemd
+      provision_command:
+        - apt-get update && apt-get install -y udev
   - name: ubuntu-18.04
     driver_config:
       run_command: /lib/systemd/systemd