Prepare for 1.1.1-pre8 release

Reviewed-by: Richard Levitte <levitte@openssl.org>

README

@@ -1,5 +1,5 @@
 
- OpenSSL 1.1.1-pre8-dev
+ OpenSSL 1.1.1-pre8 (beta) 20 Jun 2018
 
  Copyright (c) 1998-2018 The OpenSSL Project
  Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson

include/openssl/opensslv.h

@@ -40,7 +40,7 @@ extern "C" {
  *  major minor fix final patch/beta)
  */
 # define OPENSSL_VERSION_NUMBER  0x10101008L
-# define OPENSSL_VERSION_TEXT    "OpenSSL 1.1.1-pre8-dev  xx XXX xxxx"
+# define OPENSSL_VERSION_TEXT    "OpenSSL 1.1.1-pre8 (beta) 20 Jun 2018"
 
 /*-
  * The macros below are to be used for shared library (.so, .dll, ...)