Run tests on IPython 8

Author: davidesarra

tox.ini

@@ -1,9 +1,9 @@
 [tox]
 envlist =
     {py36,py37}-ipython{5,6,7}
-    py38-ipython7
-    py39-ipython7
-    py310-ipython7
+    py38-ipython{7,8}
+    py39-ipython{7,8}
+    py310-ipython{7,8}
     ; ipython73 adds compatibility with py38+
 
 [gh-actions]
@@ -20,4 +20,5 @@ deps =
     ipython5: ipython>=5.0.0,<6.0.0
     ipython6: ipython>=6.0.0,<7.0.0
     ipython7: ipython>=7.3.0,<8.0.0
+    ipython8: ipython>=8.0.0,<9.0.0
 commands = pytest --cov=jupyter_spaces --cov-report=xml --cov-report=term