distro/tests: improve VM names to avoid collisions with knot-resolver

distro/tests/arch/Vagrantfile

@@ -7,8 +7,8 @@ Vagrant.configure(2) do |config|
     config.vm.box = "archlinux/archlinux"
     config.vm.synced_folder ".", "/vagrant", disabled: true
 
-    config.vm.define "arch"  do |arch|
-        arch.vm.provision "ansible" do |ansible|
+    config.vm.define "arch_knot-dns"  do |machine|
+        machine.vm.provision "ansible" do |ansible|
             ansible.playbook = "../knot-dns-test.yaml"
         end
     end

distro/tests/centos7/Vagrantfile

@@ -7,8 +7,8 @@ Vagrant.configure(2) do |config|
     config.vm.box = "centos/7"
     config.vm.synced_folder ".", "/vagrant", disabled: true
 
-    config.vm.define "centos7"  do |centos7|
-        centos7.vm.provision "ansible" do |ansible|
+    config.vm.define "centos7_knot-dns"  do |machine|
+        machine.vm.provision "ansible" do |ansible|
             ansible.playbook = "../knot-dns-test.yaml"
         end
     end

distro/tests/debian9/Vagrantfile

@@ -7,8 +7,8 @@ Vagrant.configure(2) do |config|
     config.vm.box = "debian/stretch64"
     config.vm.synced_folder ".", "/vagrant", disabled: true
 
-    config.vm.define "debian9"  do |debian9|
-        debian9.vm.provision "ansible" do |ansible|
+    config.vm.define "debian9_knot-dns"  do |machine|
+        machine.vm.provision "ansible" do |ansible|
             ansible.playbook = "../knot-dns-test.yaml"
         end
     end

distro/tests/fedora27/Vagrantfile

@@ -7,8 +7,8 @@ Vagrant.configure(2) do |config|
     config.vm.box = "fedora/27-cloud-base"
     config.vm.synced_folder ".", "/vagrant", disabled: true
 
-    config.vm.define "fedora27"  do |fedora27|
-        fedora27.vm.provision "ansible" do |ansible|
+    config.vm.define "fedora27_knot-dns"  do |machine|
+        machine.vm.provision "ansible" do |ansible|
             ansible.playbook = "../knot-dns-test.yaml"
         end
     end

distro/tests/ubuntu1604/Vagrantfile

@@ -7,8 +7,8 @@ Vagrant.configure(2) do |config|
     config.vm.box = "generic/ubuntu1604"
     config.vm.synced_folder ".", "/vagrant", disabled: true
 
-    config.vm.define "ubuntu1604"  do |ubuntu1604|
-        ubuntu1604.vm.provision "ansible" do |ansible|
+    config.vm.define "ubuntu1604_knot-dns"  do |machine|
+        machine.vm.provision "ansible" do |ansible|
             ansible.playbook = "../knot-dns-test.yaml"
         end
     end