Allow hyperframe 5

(cherry picked from commit d8dd594)

Author: Lukasa

setup.py

@@ -61,7 +61,7 @@
         'Programming Language :: Python :: Implementation :: PyPy',
     ],
     install_requires=[
-        'hyperframe>=3.1, <5, !=4.0.0',
+        'hyperframe>=3.1, <6, !=4.0.0',
         'hpack>=2.2, <3',
     ],
     extras_require={