add python 3.9 CI configurations

ci/azure/conda_linux.yml

@@ -18,6 +18,8 @@ jobs:
         python.version: '37'
       Python38:
         python.version: '38'
+      Python39:
+        python.version: '39'
 
   steps:
   - bash: echo "##vso[task.prependpath]/usr/share/miniconda/bin"

ci/azure/conda_windows.yml

@@ -14,6 +14,8 @@ jobs:
         python.version: '37'
       Python38-windows:
         python.version: '38'
+      Python39-windows:
+        python.version: '39'
 
   steps:
   - powershell: Write-Host "##vso[task.prependpath]$env:CONDA\Scripts"

ci/azure/posix.yml

@@ -14,6 +14,8 @@ jobs:
         python.version: '3.7'
       Python38:
         python.version: '3.8'
+      Python39:
+        python.version: '3.9'
 
   steps:
   - task: UsePythonVersion@0

ci/requirements-py39.yml

@@ -0,0 +1,31 @@
+name: test_env
+channels:
+    - defaults
+    - conda-forge
+dependencies:
+    - coveralls
+    - cython
+    - ephem
+    # - netcdf4  # pulls in a different version of numpy with ImportError
+    - nose
+    # - numba  # python 3.9 compat in early 2021
+    - numpy >= 1.12.0
+    - pandas >= 0.22.0
+    - pip
+    - pytables  # tables when using pip+PyPI
+    - pytest
+    - pytest-cov
+    - pytest-mock
+    - pytest-timeout
+    - pytest-rerunfailures
+    - pytest-remotedata
+    - python=3.9
+    - pytz
+    - requests
+    - scipy >= 1.2.0
+    - shapely  # pvfactors dependency
+    # - siphon  # conda-forge
+    - statsmodels
+    - pip:
+        # - nrel-pysam>=2.0  # install error on windows
+        - pvfactors==1.4.1

docs/sphinx/source/whatsnew/v0.8.1.rst

@@ -41,6 +41,7 @@ Testing
 ~~~~~~~
 * Add airspeed velocity performance testing configuration and a few benchmarks.
   (:issue:`419`, :pull:`1049`, :pull:`1059`)
+* Add Python 3.9 CI configurations. (:issue:`1102`, :pull:`1112`)
 
 Documentation
 ~~~~~~~~~~~~~