fix GitHub Actions integration

Author: Kriechi

.github/workflows/ci.yml

@@ -19,6 +19,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@master
+      with:
+        submodules: recursive
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with:

tox.ini

@@ -1,6 +1,12 @@
 [tox]
 envlist = py36, py37, py38, pypy3, lint
 
+[gh-actions]
+python =
+    3.6: py36
+    3.7: py37
+    3.8: py38, lint
+
 [testenv]
 deps =
     pytest==5.4.3
@@ -10,7 +16,7 @@ deps =
 commands =
     pytest --cov=hyperframe {posargs}
 
-[testenv:pypy]
+[testenv:pypy3]
 # temporarily disable coverage testing on PyPy due to performance problems
 commands = pytest {posargs}