Update README to reference latest Python and Trio

.gitignore

@@ -0,0 +1 @@
+.venv

README.rst

@@ -4,7 +4,7 @@ trio_http_proxy.py
 Simple HTTP CONNECT proxy implemented with
 `Trio <https://trio.readthedocs.io>`__.
 
-Tested with Python 3.7 and Trio 0.11.0
+Tested with Python 3.8 and Trio 0.17.0
 (but other versions probably work too).
 
 

requirements.in

@@ -0,0 +1 @@
+trio

requirements.txt

@@ -0,0 +1,13 @@
+#
+# This file is autogenerated by pip-compile
+# To update, run:
+#
+#    pip-compile
+#
+async-generator==1.10     # via trio
+attrs==20.2.0             # via trio
+idna==2.10                # via trio
+outcome==1.0.1            # via trio
+sniffio==1.1.0            # via trio
+sortedcontainers==2.2.2   # via trio
+trio==0.17.0              # via -r requirements.in