cmake: update minimum version to 3.8.0

Related-to: wdas#70
Signed-off-by: David Aguilar <[email protected]>

CMakeLists.txt

@@ -31,12 +31,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 
-## CMake compatibility issues: don't modify this, please!
-CMAKE_MINIMUM_REQUIRED( VERSION 2.4.6 )
-MARK_AS_ADVANCED(CMAKE_BACKWARDS_COMPATIBILITY)
-## allow more human readable "if then else" constructs
-SET( CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS TRUE )
-## disable rpath when linking
+CMAKE_MINIMUM_REQUIRED( VERSION 3.8.0 )
 SET( CMAKE_SKIP_RPATH TRUE )
 
 ## project name & version