Drop CI for OpenSSL 1.0.2 (#953)

* Drop CI for OpenSSL 1.0.2

* Delete code for coverage reasons

* Bump minimum cryptography version
diff --git a/setup.py b/setup.py
index 6f3afd7..08769d2 100755
--- a/setup.py
+++ b/setup.py
@@ -94,7 +94,7 @@
         package_dir={"": "src"},
         install_requires=[
             # Fix cryptographyMinimum in tox.ini when changing this!
-            "cryptography>=2.8",
+            "cryptography>=3.2",
             "six>=1.5.2",
         ],
         extras_require={