upgrade twine for release (#344)

Author: Jack Chen

setup.py

@@ -20,7 +20,7 @@
     "pytest-cov==4.*",
     "pytest-vcr==1.*",
     "pytest==7.*",
-    "twine==4.*",
+    "twine==5.*;python_version>='3.8'",  # TODO: remove python pin when 3.7 is dropped
     "types-requests",
     "types-urllib3",
     "vcrpy==4.*",  # TODO: vcrpy v5 requires Python 3.8+