Prepare for 3.0 alpha 6

Reviewed-by: Nicola Tuveri <nic.tuv@gmail.com>

CHANGES.md

@@ -21,7 +21,7 @@ OpenSSL Releases
 OpenSSL 3.0
 -----------
 
-### Changes between 1.1.1 and 3.0 alpha 5 [16 Jul 2020]
+### Changes between 1.1.1 and 3.0 [xx XXX xxxx]
 
  * Deprecated the `ENGINE` API.  Engines should be replaced with providers
    going forward.

NEWS.md

@@ -18,7 +18,7 @@ OpenSSL Releases
 OpenSSL 3.0
 -----------
 
-### Major changes between OpenSSL 1.1.1 and OpenSSL 3.0 alpha 5 [in pre-release]
+### Major changes between OpenSSL 1.1.1 and OpenSSL 3.0 [under development]
 
   * Deprecated the `ENGINE` API.
   * Added `OPENSSL_CTX`, a libcrypto library context.

VERSION.dat

@@ -1,7 +1,7 @@
 MAJOR=3
 MINOR=0
 PATCH=0
-PRE_RELEASE_TAG=alpha5
+PRE_RELEASE_TAG=alpha6-dev
 BUILD_METADATA=
-RELEASE_DATE="16 Jul 2020"
+RELEASE_DATE=""
 SHLIB_VERSION=3