Bump minimum cmake version to 3.5 to avoid deprecation warning

Building msgpack gives currently gives the following warning:
"CMake Deprecation Warning at CMakeLists.txt:1 (CMAKE_MINIMUM_REQUIRED):
  Compatibility with CMake < 3.5 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions."

Reuse same solution as fc18087cdf as the
policy CMP0060 introduced in cmake 3.3 causes problems with when linking
for 32-bit otherwise.

CMakeLists.txt

@@ -1,9 +1,12 @@
-CMAKE_MINIMUM_REQUIRED (VERSION 2.8.12)
-
-IF ((CMAKE_VERSION VERSION_GREATER 3.1) OR
-    (CMAKE_VERSION VERSION_EQUAL 3.1))
-    CMAKE_POLICY(SET CMP0054 NEW)
-ENDIF ()
+if(${CMAKE_VERSION} VERSION_GREATER "3.4")
+    CMAKE_MINIMUM_REQUIRED (VERSION 3.5)
+else()
+    CMAKE_MINIMUM_REQUIRED (VERSION 2.8.12)
+    IF ((CMAKE_VERSION VERSION_GREATER 3.1) OR
+        (CMAKE_VERSION VERSION_EQUAL 3.1))
+        CMAKE_POLICY(SET CMP0054 NEW)
+    ENDIF ()
+endif()
 
 OPTION (MSGPACK_BUILD_TESTS "Build msgpack tests." OFF)
 OPTION (MSGPACK_GEN_COVERAGE "Enable running gcov to get a test coverage report." OFF)
@@ -38,7 +41,7 @@ IF (BIGENDIAN)
     SET(MSGPACK_ENDIAN_LITTLE_BYTE 0)
 ELSE ()
     SET(MSGPACK_ENDIAN_BIG_BYTE 0)
-        SET(MSGPACK_ENDIAN_LITTLE_BYTE 1)
+    SET(MSGPACK_ENDIAN_LITTLE_BYTE 1)
 ENDIF ()
 
 CONFIGURE_FILE (

ci/build_cmake.sh

@@ -20,12 +20,13 @@ if [ "${ARCH}" == "32" ]
 then
     export BIT32="ON"
     export ARCH_FLAG="-m32"
+    ZLIB32="-DZLIB_LIBRARY=/usr/lib32/libz.a"
 else
     export BIT32="OFF"
     export ARCH_FLAG="-m64"
 fi
 
-cmake -DMSGPACK_BUILD_TESTS=ON -DMSGPACK_32BIT=${BIT32} -DBUILD_SHARED_LIBS=${SHARED} -DMSGPACK_CHAR_SIGN=${CHAR_SIGN} -DCMAKE_CXX_FLAGS="${ARCH_FLAG} ${CXXFLAGS} ${SAN}" -DCMAKE_C_FLAGS="${CFLAGS} ${SAN}" ..
+cmake -DMSGPACK_BUILD_TESTS=ON -DMSGPACK_32BIT=${BIT32} -DBUILD_SHARED_LIBS=${SHARED} -DMSGPACK_CHAR_SIGN=${CHAR_SIGN} -DCMAKE_CXX_FLAGS="${ARCH_FLAG} ${CXXFLAGS} ${SAN}" -DCMAKE_C_FLAGS="${CFLAGS} ${SAN}" ${ZLIB32} ..
 
 ret=$?
 if [ $ret -ne 0 ]

example/cmake/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.0)
+cmake_minimum_required (VERSION 3.5)
 project (example)
 
 if(EXAMPLE_MSGPACK_EMBEDDED)