CMake update minimum version to 2.8.12 (#639)
CMake update minimum version to 2.8.12 (#639)

File:
CMakeLists.txt

Notes:
Following CMake's advice, Update the minimum required version.

Credit:
Jun Tseng
libssh2/libssh2,libssh2/libssh2,libssh2/libssh2,libssh2/libssh2