message: Enable python 3.9 build on macOS
  This PR enables python 3.9 build on macOS, as tf-nightly
  is available with macOS now.
diff: @@ -147,7 +147,7 @@ jobs:
  runs-on: macos-latest
  strategy:
  matrix:
  - python: ['3.6', '3.7', '3.8']
  + python: ['3.6', '3.7', '3.8', '3.9']
  steps:
  - uses: actions/checkout@v2
  - uses: actions/download-artifact@v1
  @@ -184,7 +184,7 @@ jobs:
  runs-on: macos-latest
  strategy:
  matrix:
  - python: ['3.7', '3.8']
  + python: ['3.7', '3.8', '3.9']
  steps:
  - uses: actions/checkout@v2
  - uses: actions/download-artifact@v1
  @@ -451,6 +451,10 @@ jobs:
  with:
  name: macOS-3.8-wheel
  path: macOS-3.8-wheel
  + - uses: actions/download-artifact@v1
  + with:
  + name: macOS-3.9-wheel
  + path: macOS-3.9-wheel
  - uses: actions/download-artifact@v1
  with:
  name: Linux-3.6-wheel
  @@ -489,6 +493,7 @@ jobs:
  cp macOS-3.6-wheel/*.whl wheelhouse/
  cp macOS-3.7-wheel/*.whl wheelhouse/
  cp macOS-3.8-wheel/*.whl wheelhouse/
  + cp macOS-3.9-wheel/*.whl wheelhouse/
  cp Linux-3.6-wheel/*.whl wheelhouse/
  cp Linux-3.7-wheel/*.whl wheelhouse/
  cp Linux-3.8-wheel/*.whl wheelhouse/
  @@ -549,7 +554,7 @@ jobs:
  runs-on: macos-latest
  strategy:
  matrix:
  - python: ['3.6', '3.7', '3.8']
  + python: ['3.6', '3.7', '3.8', '3.9']
  steps:
  - uses: actions/download-artifact@v1
  with:
  @@ -676,6 +681,10 @@ jobs:
  with:
  name: macOS-3.8-nightly
  path: macOS-3.8-nightly
  + - uses: actions/download-artifact@v1
  + with:
  + name: macOS-3.9-nightly
  + path: macOS-3.9-nightly
  - uses: actions/download-artifact@v1
  with:
  name: Linux-3.6-nightly
  @@ -714,6 +723,7 @@ jobs:
  cp macOS-3.6-nightly/*.whl dist/
  cp macOS-3.7-nightly/*.whl dist/
  cp macOS-3.8-nightly/*.whl dist/
  + cp macOS-3.9-nightly/*.whl dist/
  cp Linux-3.6-nightly/*.whl dist/
  cp Linux-3.7-nightly/*.whl dist/
  cp Linux-3.8-nightly/*.whl dist/
  