Use Azure Pipelines itself to generate and run test matrix from Python script

Instead of having to run a script on the developer's system and then committing the result, Azure Pipelines itself can run a modification of that script and reuse the variable it sets in later steps to determine the test matrices.

Reference: https://docs.microsoft.com/en-us/azure/devops/pipelines/process/phases?view=azure-devops&tabs=yaml#multi-configuration

With this, `/azure-pipelines.yml` no longer needs to be treated like a committed generated artifact!

Closes #30.

azure-pipelines.yml

@@ -1,156 +1,46 @@
-# Generated by `generate_azure_pipelines_yml.py`
-# Please edit template in `ci/`
-
 jobs:
+- job: MatricesGenerator
+  displayName: Matrices Generator
+  pool:
+    vmImage: 'ubuntu-16.04'
+  steps:
+    - task: UsePythonVersion@0
+      inputs:
+        versionSpec: '3.7'
+        addToPath: true
+    - bash: python generate_azure_pipelines_matrices.py
+      name: mtrx
+      displayName: Generate test matrices and set variables in Azure Pipelines
+
 - job: Mac
+  dependsOn: MatricesGenerator
   pool:
-    vmImage: macOS-10.14
-  steps:
-  - script: brew install p7zip
-    displayName: Install 7zip
-  - template: ci/steps.yml
+    vmImage: 'macOS-10.14'
   strategy:
-    matrix:
-      QT 5.11.3 mac desktop clang_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.11.3
-        HOST: mac
-        TARGET: desktop
-        ARCH: clang_64
-        ARCHDIR: clang_64
-      QT 5.12.3 mac desktop clang_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.12.3
-        HOST: mac
-        TARGET: desktop
-        ARCH: clang_64
-        ARCHDIR: clang_64
-      QT 5.13.0 mac desktop clang_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: mac
-        TARGET: desktop
-        ARCH: clang_64
-        ARCHDIR: clang_64
-      QT 5.13.0 mac ios ios:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: mac
-        TARGET: ios
-        ARCH: ios
-        ARCHDIR: ios
+    matrix: $[ dependencies.MatricesGenerator.outputs['mtrx.mac'] ]
+  steps:
+    - script: brew install p7zip
+      displayName: Install 7zip
+    - template: ci/steps.yml
+
 - job: Windows
+  dependsOn: MatricesGenerator
   pool:
-    vmImage: vs2017-win2016
-  steps:
-  - template: ci/steps.yml
+    vmImage: 'vs2017-win2016'
   strategy:
-    matrix:
-      QT 5.11.3 windows desktop win64_msvc2017_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.11.3
-        HOST: windows
-        TARGET: desktop
-        ARCH: win64_msvc2017_64
-        ARCHDIR: msvc2017_64
-      QT 5.11.3 windows desktop win32_msvc2015:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.11.3
-        HOST: windows
-        TARGET: desktop
-        ARCH: win32_msvc2015
-        ARCHDIR: msvc2015
-      QT 5.12.3 windows desktop win64_msvc2017_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.12.3
-        HOST: windows
-        TARGET: desktop
-        ARCH: win64_msvc2017_64
-        ARCHDIR: msvc2017_64
-      QT 5.12.3 windows desktop win32_msvc2017:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.12.3
-        HOST: windows
-        TARGET: desktop
-        ARCH: win32_msvc2017
-        ARCHDIR: msvc2017
-      QT 5.13.0 windows desktop win64_msvc2017_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: windows
-        TARGET: desktop
-        ARCH: win64_msvc2017_64
-        ARCHDIR: msvc2017_64
-      QT 5.13.0 windows desktop win64_msvc2015_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: windows
-        TARGET: desktop
-        ARCH: win64_msvc2015_64
-        ARCHDIR: msvc2015_64
-      QT 5.13.0 windows desktop win64_mingw73:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: windows
-        TARGET: desktop
-        ARCH: win64_mingw73
-        ARCHDIR: mingw73_64
-      QT 5.13.0 windows desktop win32_msvc2017:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: windows
-        TARGET: desktop
-        ARCH: win32_msvc2017
-        ARCHDIR: msvc2017
-      QT 5.13.0 windows desktop win32_mingw73:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: windows
-        TARGET: desktop
-        ARCH: win32_mingw73
-        ARCHDIR: mingw73_32
+    matrix: $[ dependencies.MatricesGenerator.outputs['mtrx.windows'] ]
+  steps:
+    - template: ci/steps.yml
+
 - job: Linux
+  dependsOn: MatricesGenerator
   pool:
-    vmImage: ubuntu-16.04
-  steps:
-  - template: ci/steps.yml
+    vmImage: 'ubuntu-16.04'
   strategy:
-    matrix:
-      QT 5.11.3 linux desktop gcc_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.11.3
-        HOST: linux
-        TARGET: desktop
-        ARCH: gcc_64
-        ARCHDIR: gcc_64
-      QT 5.12.3 linux desktop gcc_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.12.3
-        HOST: linux
-        TARGET: desktop
-        ARCH: gcc_64
-        ARCHDIR: gcc_64
-      QT 5.13.0 linux desktop gcc_64:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: linux
-        TARGET: desktop
-        ARCH: gcc_64
-        ARCHDIR: gcc_64
-      QT 5.13.0 linux android android_x86:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: linux
-        TARGET: android
-        ARCH: android_x86
-        ARCHDIR: android_x86
-      QT 5.13.0 linux android android_armv7:
-        PYTHON_VERSION: '3.7'
-        QT_VERSION: 5.13.0
-        HOST: linux
-        TARGET: android
-        ARCH: android_armv7
-        ARCHDIR: android_armv7
+    matrix: $[ dependencies.MatricesGenerator.outputs['mtrx.linux'] ]
+  steps:
+    - template: ci/steps.yml
+
 - job: LinuxSpecificMirror
   displayName: Linux (Specific Mirror)
   variables:
@@ -162,6 +52,6 @@ jobs:
     ARCHDIR: android_armv7
     QT_BASE_MIRROR: http://mirrors.ocf.berkeley.edu/qt/
   pool:
-    vmImage: ubuntu-16.04
+    vmImage: 'ubuntu-16.04'
   steps:
-  - template: ci/steps.yml
+    - template: ci/steps.yml