ENH: Add 3.8 wheel build

Author: larsoner

azure-pipelines.yml

@@ -8,7 +8,7 @@ trigger:
       - '*'
 variables:
   CIBW_BUILDING: "true"
-  CIBW_SKIP: "cp27-* cp34-*"
+  CIBW_SKIP: "cp27-* cp34-* pp27-*"
   CIBW_TEST_COMMAND: "python -c \"import rtmixer; print(rtmixer.__version__)\""
   CIBW_BUILD_VERBOSITY: "2"
   CIBW_BEFORE_BUILD: "pip install -U pip setuptools"
@@ -29,7 +29,7 @@ jobs:
         path: $(System.DefaultWorkingDirectory)/wheelhouse
         artifact: deployLinux
 - job: macos
-  pool: {vmImage: 'macOS-10.13'}
+  pool: {vmImage: 'macOS-10.15'}
   steps:
     - task: UsePythonVersion@0
     - bash: |
@@ -50,6 +50,8 @@ jobs:
     - {task: UsePythonVersion@0, inputs: {versionSpec: '3.6', architecture: x64}}
     - {task: UsePythonVersion@0, inputs: {versionSpec: '3.7', architecture: x86}}
     - {task: UsePythonVersion@0, inputs: {versionSpec: '3.7', architecture: x64}}
+    - {task: UsePythonVersion@0, inputs: {versionSpec: '3.8', architecture: x86}}
+    - {task: UsePythonVersion@0, inputs: {versionSpec: '3.8', architecture: x64}}
     - bash: |
         git submodule update --init --recursive
         python -m pip install --upgrade pip