Hypothetically fixes pyOpenSSL tests (#805)

* fix openssl CLI testing for 1.1.1

* various 1.1.1 related fixes

some of which are just admitting TLS 1.3 is fundamentally different and
pinning the tests to TLS 1.2

* flake8 fixes

* allow travis_infra env var through

* fix twisted
diff --git a/setup.py b/setup.py
index 3728795..5387d2a 100755
--- a/setup.py
+++ b/setup.py
@@ -49,7 +49,7 @@
     read_file("README.rst") + "\n\n" +
     "Release Information\n" +
     "===================\n\n" +
-    re.search("(\d{2}.\d.\d \(.*?\)\n.*?)\n\n\n----\n",
+    re.search(r"(\d{2}.\d.\d \(.*?\)\n.*?)\n\n\n----\n",
               read_file("CHANGELOG.rst"), re.S).group(1) +
     "\n\n`Full changelog " +
     "<{uri}en/stable/changelog.html>`_.\n\n"