metadata/readme updates about dropped versions

README.md

@@ -37,10 +37,10 @@ and the
 
 Magic-Wormhole is released under the MIT license, see the `LICENSE` file for details.
 
-This library is compatible with Python 3.6 and higher (tested against 3.6,
-3.7, 3.8, and 3.9). It also still works with Python 2.7 and 3.5, although
-these are no longer supported by upstream libraries like Cryptography, so it
-may stop working at any time.
+This library is compatible with Python 3.8 and higher (tested against
+3.8, and 3.9). It also still works with Python 2.7 although that is no
+longer supported by upstream libraries like Cryptography, so it may
+stop working at any time.
 
 ## Packaging, Installation
 

docs/welcome.md

@@ -312,8 +312,7 @@ trial wormhole.test.test_cli.PregeneratedCode.test_file_tor
 ```
 
 Developers can also just clone the source tree and run `tox` to run the unit
-tests on all supported (and installed) versions of python: 2.7, 3.4, 3.5, and
-3.6.
+tests on all supported (and installed) versions of python: 2.7, 3.7 and 3.8.
 
 ### Troubleshooting
 
@@ -336,8 +335,7 @@ Relevant [xkcd](https://xkcd.com/949/) :-)
 
 This library is released under the MIT license, see LICENSE for details.
 
-This library is compatible with python2.7, 3.4 (non-Windows-only), 3.5, and
-3.6 .
+This library is compatible with python2.7, 3.7 and 3.8 .
 
 
 <!-- footnotes -->

setup.py

@@ -11,8 +11,6 @@ trove_classifiers = [
     "Programming Language :: Python :: 2",
     "Programming Language :: Python :: 2.7",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.5",
-    "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: Implementation :: CPython",