Tests: Add Fedora-27 to packaging tests

Replace Fedora-25 with Fedora-27 and fix old references in
`TESTING.asciidoc`.

Relates #27434

TESTING.asciidoc

@@ -351,8 +351,8 @@ These are the linux flavors the Vagrantfile currently supports:
 * debian-9 aka stretch, the current debian stable distribution
 * centos-6
 * centos-7
-* fedora-25
 * fedora-26
+* fedora-27
 * oel-6 aka Oracle Enterprise Linux 6
 * oel-7 aka Oracle Enterprise Linux 7
 * sles-12
@@ -428,23 +428,23 @@ sudo -E bats $BATS_TESTS/*.bats
 You can also use Gradle to prepare the test environment and then starts a single VM:
 
 -------------------------------------------------
-gradle vagrantFedora25#up
+gradle vagrantFedora27#up
 -------------------------------------------------
 
 Or any of vagrantCentos6#up, vagrantCentos7#up, vagrantDebian8#up,
-vagrantFedora25#up, vagrantOel6#up, vagrantOel7#up, vagrantOpensuse13#up,
-vagrantSles12#up, vagrantUbuntu1404#up, vagrantUbuntu1604#up.
+vagrantDebian9#up, vagrantFedora26#up, vagrantFedora27#up, vagrantOel6#up, vagrantOel7#up,
+vagrantOpensuse42#up,vagrantSles12#up, vagrantUbuntu1404#up, vagrantUbuntu1604#up.
 
 Once up, you can then connect to the VM using SSH from the elasticsearch directory:
 
 -------------------------------------------------
-vagrant ssh fedora-25
+vagrant ssh fedora-27
 -------------------------------------------------
 
 Or from another directory:
 
 -------------------------------------------------
-VAGRANT_CWD=/path/to/elasticsearch vagrant ssh fedora-25
+VAGRANT_CWD=/path/to/elasticsearch vagrant ssh fedora-27
 -------------------------------------------------
 
 Note: Starting vagrant VM outside of the elasticsearch folder requires to

Vagrantfile

@@ -60,14 +60,14 @@ Vagrant.configure(2) do |config|
     config.vm.box = "elastic/oraclelinux-7-x86_64"
     rpm_common config
   end
-  config.vm.define "fedora-25" do |config|
-    config.vm.box = "elastic/fedora-25-x86_64"
-    dnf_common config
-  end
   config.vm.define "fedora-26" do |config|
     config.vm.box = "elastic/fedora-26-x86_64"
     dnf_common config
   end
+  config.vm.define "fedora-27" do |config|
+    config.vm.box = "elastic/fedora-27-x86_64"
+    dnf_common config
+  end
   config.vm.define "opensuse-42" do |config|
     config.vm.box = "elastic/opensuse-42-x86_64"
     opensuse_common config

buildSrc/src/main/groovy/org/elasticsearch/gradle/vagrant/VagrantTestPlugin.groovy

@@ -19,8 +19,8 @@ class VagrantTestPlugin implements Plugin<Project> {
             'centos-7',
             'debian-8',
             'debian-9',
-            'fedora-25',
             'fedora-26',
+            'fedora-27',
             'oel-6',
             'oel-7',
             'opensuse-42',