feat: add support for Python 3.10 (#882)

diff --git a/noxfile.py b/noxfile.py
index caeb272..2e6e889 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -86,7 +86,7 @@
     session.run("black", *BLACK_PATHS)
 
 
-@nox.session(python=["3.6", "3.7", "3.8", "3.9"])
+@nox.session(python=["3.6", "3.7", "3.8", "3.9", "3.10"])
 def unit(session):
     constraints_path = str(
         CURRENT_DIRECTORY / "testing" / f"constraints-{session.python}.txt"