Add Python 3.9 to test matrix and classifiers

.github/workflows/ci.yml

@@ -16,5 +16,8 @@ jobs:
       - uses: actions/setup-python@v1
         with:
           python-version: "3.8"
+      - uses: actions/setup-python@v1
+        with:
+          python-version: "3.9"
       - run: python -m pip install --upgrade tox
       - run: tox

setup.cfg

@@ -16,6 +16,7 @@ classifiers =
 	Programming Language :: Python :: 3.6
 	Programming Language :: Python :: 3.7
 	Programming Language :: Python :: 3.8
+	Programming Language :: Python :: 3.9
 	Topic :: Software Development :: Disassemblers
 	Topic :: System
 	Topic :: Utilities

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 # When adding a new Python version here, please also update the list of Python versions called by the GitHub Actions workflow (.github/workflows/ci.yml).
-envlist = py{36,37,38},flake8,mypy,package
+envlist = py{36,37,38,39},flake8,mypy,package
 
 [testenv]
 commands = python -m unittest discover --start-directory ./tests