Support Python 3.8, 3.9, and 3.10 and drop support for 3.6 (#60)

* Support Python 3.8, 3.9, and 3.10 and drop support for 3.6

* Provide upper bound for pytest-postgresql<4.0.0

This is necessary because in the 4.0.0 release pytest-postgresql dropped support for psycopg2: dbfixtures/pytest-postgresql#487

Author: jeancochrane

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: [3.6.x, 3.7.x]
+        python: [3.7.x, 3.8.x, 3.9.x, 3.10.x]
         sqlalchemy: [1.2.*, 1.3.*, 1.4.*]
     services:
       postgres:

setup.py

@@ -21,7 +21,7 @@ def readme():
                       'SQLAlchemy>=1.2.2',
                       'Flask-SQLAlchemy>=2.3',
                       'packaging>=14.1'],
-    extras_require={'tests': ['pytest-postgresql>=2.4.0', 'psycopg2-binary', 'pytest>=6.0.1']},
+    extras_require={'tests': ['pytest-postgresql>=2.4.0,<4.0.0', 'psycopg2-binary', 'pytest>=6.0.1']},
     classifiers=[
         'Development Status :: 4 - Beta',
         'Environment :: Plugins',