Drop OpenSSL 0.9.8 (#2978)

* Drop OpenSSL 0.9.8

* Drop this test, it's not relevant any longer

* unused import

* Remove CRYPTOGRAPHY_ALLOW_OPENSSL_098=1 from our tox

* removed unused code for Cryptography_HAS_PKEY_CTX

* return unused code for _AESCTRCipherContext

* syntax :-(

* remove some unused tests and skips

* remove unused code for Cryptography_HAS_PBKDF2_HMAC

* Revert "return unused code for _AESCTRCipherContext"

This reverts commit 7d149729205aa4c9735eb322414b167a75b302df.

* Remove unused RSA code

* Remove unused test code for conditional bindings

* Remove unused dsa code

* unused import

* Remove unused x509 extension code

* Remove unused EC code

* Attempt to remove unused DER key loading code

* document this

* grammar

* Added back this paragraph

* Update docs
diff --git a/docs/hazmat/backends/openssl.rst b/docs/hazmat/backends/openssl.rst
index f488a8b..8bc7dac 100644
--- a/docs/hazmat/backends/openssl.rst
+++ b/docs/hazmat/backends/openssl.rst
@@ -3,9 +3,8 @@
 OpenSSL backend
 ===============
 
-The `OpenSSL`_ C library. Cryptography supports version ``0.9.8e`` (present in
-Red Hat Enterprise Linux 5) and greater. Earlier versions may work but are
-**not tested or supported**.
+The `OpenSSL`_ C library. Cryptography supports OpenSSL version ``1.0.0`` and
+greater.
 
 .. data:: cryptography.hazmat.backends.openssl.backend
 
diff --git a/docs/hazmat/bindings/openssl.rst b/docs/hazmat/bindings/openssl.rst
index 8935093..8aef488 100644
--- a/docs/hazmat/bindings/openssl.rst
+++ b/docs/hazmat/bindings/openssl.rst
@@ -6,8 +6,7 @@
 .. currentmodule:: cryptography.hazmat.bindings.openssl.binding
 
 These are `CFFI`_ bindings to the `OpenSSL`_ C library. Cryptography supports
-version ``0.9.8e`` (present in Red Hat Enterprise Linux 5) and greater. Earlier
-versions may work but are **not tested or supported**.
+OpenSSL version ``1.0.0`` and greater.
 
 .. class:: cryptography.hazmat.bindings.openssl.binding.Binding()