Testing build matrix

Changes azure-pipelines to have 3 different stages: fedora-latest,
centos-7 and centos-8.

tests/azure/azure-pipelines.yml

@@ -17,40 +17,48 @@ trigger:
 pool:
   vmImage: 'ubuntu-18.04'
 
-jobs:
-- job: RunLinters
-  displayName: Run Linters
-  steps:
-  - task: UsePythonVersion@0
-    inputs:
-      versionSpec: '3.6'
+stages:
+- stage: Linters
+  jobs:
+  - job: RunLinters
+    displayName: Run Linters
+    steps:
+    - task: UsePythonVersion@0
+      inputs:
+        versionSpec: '3.6'
 
-  - script: python -m pip install --upgrade pip setuptools wheel
-    displayName: Install tools
+    - script: python -m pip install --upgrade pip setuptools wheel
+      displayName: Install tools
 
-  - script: pip install pydocstyle flake8
-    displayName: Install dependencies
+    - script: pip install pydocstyle flake8
+      displayName: Install dependencies
 
-  - script: flake8 .
-    displayName: Run flake8 checks
+    - script: flake8 .
+      displayName: Run flake8 checks
 
-  - script: pydocstyle .
-    displayName: Verify docstings
+    - script: pydocstyle .
+      displayName: Verify docstings
 
-- template: templates/playbook_tests.yml
-  parameters:
-    group_number: 1
-    number_of_groups: 3
-    build_number: $(Build.BuildNumber)
+- stage: Centos7
+  dependsOn: []
+  jobs:
+  - template: templates/group_tests.yml
+    parameters:
+      build_number: $(Build.BuildNumber)
+      scenario: centos-7
 
-- template: templates/playbook_tests.yml
-  parameters:
-    group_number: 2
-    number_of_groups: 3
-    build_number: $(Build.BuildNumber)
+- stage: Centos8
+  dependsOn: []
+  jobs:
+  - template: templates/group_tests.yml
+    parameters:
+      build_number: $(Build.BuildNumber)
+      scenario: centos-8
 
-- template: templates/playbook_tests.yml
-  parameters:
-    group_number: 3
-    number_of_groups: 3
-    build_number: $(Build.BuildNumber)
+- stage: FedoraLatest
+  dependsOn: []
+  jobs:
+  - template: templates/group_tests.yml
+    parameters:
+      build_number: $(Build.BuildNumber)
+      scenario: fedora-latest