Added badtime.pem vector (#4179)

* Added badtime.pem vector

In connection with forthcoming PR to fix #4158

* shortened line, corrected and->and
diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index 2eb4749..fec0363 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -176,6 +176,8 @@
   a distinguished name with an ``x500UniqueIdentifier``.
 * ``utf8-dnsname.pem`` - A certificate containing non-ASCII characters in the
   DNS name entries of the SAN extension.
+* ``badasn1time.pem`` - A certificate containing an incorrectly specified
+  UTCTime in its validity->not_after.
 
 Custom X.509 Vectors
 ~~~~~~~~~~~~~~~~~~~~