Rename 'rack-01' to 'default' in devops templates

fuel-qa requires 'default' name for default rack [0]

[0] https://github.com/openstack/fuel-qa/blob/master/fuelweb_test/models/fuel_web_client.py#L3222

Change-Id: I1aa84ff6280647c836ba0ad3d83f42c6d0deec6a
Closes-bug:1669777

gates_tests/devops_templates/default.yaml

@@ -78,7 +78,7 @@ template:
           vlan_end: 1000
 
     groups:
-     - name: rack-01
+     - name: default
        driver:
          name: devops.driver.libvirt
          params:

system_test/tests_templates/devops_configs/centos_master.yaml

@@ -87,7 +87,7 @@ address_pools:
       tag: 103
 
 groups:
- - name: rack-01
+ - name: default
    driver:
      name: devops.driver.libvirt.libvirt_driver
      params:

system_test/tests_templates/devops_configs/default.yaml

@@ -87,7 +87,7 @@ address_pools:
       tag: 103
 
 groups:
- - name: rack-01
+ - name: default
    driver:
      name: devops.driver.libvirt.libvirt_driver
      params:

system_test/tests_templates/devops_configs/multipath.yaml

@@ -90,7 +90,7 @@ address_pools:
       tag: 103
 
 groups:
- - name: rack-01
+ - name: default
    driver:
      name: devops.driver.libvirt.libvirt_driver
      params:

system_test/tests_templates/devops_configs/public_api.yaml

@@ -97,7 +97,7 @@ address_pools:
       tag: 103
 
 groups:
- - name: rack-01
+ - name: default
    driver:
      name: devops.driver.libvirt.libvirt_driver
      params: