Refresh Python dependencies

Author: mdmintz

requirements.txt

@@ -16,6 +16,7 @@ sortedcontainers==2.4.0
 certifi>=2021.10.8
 six==1.16.0
 nose==1.3.7
+sniffio;python_version>="3.7"
 ipdb==0.13.4;python_version<"3.5"
 ipdb==0.13.9;python_version>="3.5"
 parso==0.7.1;python_version<"3.6"

setup.py

@@ -132,6 +132,7 @@
         "certifi>=2021.10.8",
         "six==1.16.0",
         "nose==1.3.7",
+        'sniffio;python_version>="3.7"',  # For "trio". (Funnier under "nose")
         'ipdb==0.13.4;python_version<"3.5"',
         'ipdb==0.13.9;python_version>="3.5"',
         'parso==0.7.1;python_version<"3.6"',