Add support for Python 3.9 (qiskit-community#505)

* Add support for Python 3.9

Python 3.9.0 was released on 10-05-2020, this commits marks the support
of Python 3.9 in qiskit-ignis. It adds the supported python version in
the package metadata and updates the CI configuration to run test jobs
on Python 3.9.

* Build from master for aer 3.9 support

* Split aer install into separate tox job

* Use tox -epy39 for 3.9 jobs

* Tweak gha condition

* Fix 3.9 reverse conditions in gha config

* Remove 3.9 windows job until aer release

(cherry picked from commit fddd1e5)

.github/workflows/main.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
         os: ["macOS-latest", "ubuntu-latest"]
     steps:
       - uses: actions/checkout@v2
@@ -31,12 +31,11 @@ jobs:
         run: python -m pip install -U tox setuptools virtualenv wheel
       - name: Install and Run Tests
         run: tox -e py
-        if: runner.os != 'macOS'
+        if: matrix.python-version != '3.9'
       - name: Install and Run Tests
-        env:
-          QISKIT_IN_PARALLEL: TRUE
-        run: tox -e py
-        if: runner.os == 'macOS'
+        run: tox -e py39
+        if: matrix.python-version == '3.9'
+
   tests-no-opt:
     name: tests-python3.8-no-optional-dependencies
     runs-on: ${{ matrix.os }}
@@ -68,9 +67,12 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
+        # TODO: Add 3.9 to the list after aer 0.8.0 release
         python-version: [3.6, 3.7, 3.8]
     steps:
       - uses: actions/checkout@v2
+      - name: Add msbuild to PATH
+        uses: microsoft/setup-msbuild@v1.0.2
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v2
         with:
@@ -90,6 +92,7 @@ jobs:
       - name: Install and Run Tests
         run: tox --sitepackages -epy
         shell: bash -l {0}
+
   lint:
     name: lint
     runs-on: ubuntu-latest

requirements-dev.txt

@@ -1,15 +1,15 @@
 pylint==2.4.4
 pycodestyle
-qiskit-aer>=0.3.0
+qiskit-aer>=0.3.0;python_version<'3.9'
 scikit-learn>=0.17
 Sphinx>=2.1
 sphinx-rtd-theme>=0.4.0
 sphinx-tabs>=1.1.11 
 sphinx-autodoc-typehints
 stestr>=2.5.0
 ddt>=1.2.0,!=1.4.0
-jupyter
-jupyter-sphinx
+jupyter;python_version<'3.9'
+jupyter-sphinx;python_version<'3.9'
 reno
 matplotlib
 pyfakefs

setup.py

@@ -73,6 +73,7 @@
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Topic :: Scientific/Engineering",
     ],
     keywords="qiskit sdk quantum",

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 2.1
-envlist = py36, py37, py38, lint
+envlist = py36, py37, py38, py39, lint
 skipsdist = True
 
 [testenv]
@@ -20,6 +20,14 @@ commands =
     pip install -U -c constraints.txt -r{toxinidir}/requirements-dev.txt
     pip check
     stestr run {posargs}
+# Remove after qiskit-aer 0.8.0 release:
+[testenv:py39]
+commands =
+    pip install -U -c constraints.txt git+https://github.com/Qiskit/qiskit-terra.git
+    pip install -U -c constraints.txt git+https://github.com/Qiskit/qiskit-aer.git
+    pip install -U -c constraints.txt -r{toxinidir}/requirements-dev.txt
+    pip check
+    stestr run {posargs}
 
 [testenv:no-opt]
 deps =