CMake 3.13.0-rc1 version update

Source/CMakeVersion.cmake

 # CMake version number components.
 set(CMake_VERSION_MAJOR 3)
-set(CMake_VERSION_MINOR 12)
-set(CMake_VERSION_PATCH 20181003)
-#set(CMake_VERSION_RC 1)
+set(CMake_VERSION_MINOR 13)
+set(CMake_VERSION_PATCH 0)
+set(CMake_VERSION_RC 1)

Utilities/Release/upload_release.cmake

 set(CTEST_RUN_CURRENT_SCRIPT 0)
 if(NOT VERSION)
- set(VERSION 3.12)
+ set(VERSION 3.13)
 endif()
 if(NOT DEFINED PROJECT_PREFIX)
   set(PROJECT_PREFIX cmake-${VERSION})