Remove graphics on MacOS -> X11 deprecated and cannot be found by travis

.travis.yml

@@ -50,6 +50,8 @@ matrix:
           - libxml++2.6-dev
           - perl
           - python
+          - readline	# added to fit Icarus installation requirement
+          - termcap		# added to fit Icarus installation requirement
           - texinfo
           - time
           - valgrind
@@ -73,7 +75,6 @@ matrix:
           - gawk
           - libxml++
           - qt5
-          - x11
 
 before_install:
   - source .travis/common.sh

CMakeLists.txt

@@ -22,7 +22,11 @@ project("OPENFPGA" C CXX)
 
 # Options
 # Option to enable/disable graphic in compilation
+if (APPLE)
+option(ENABLE_VPR_GRAPHICS "Disables VPR graphics" OFF)
+else ()
 option(ENABLE_VPR_GRAPHICS "Enables VPR graphics" ON)
+endif ()
 
 # Version number
 set(OPENFPGA_VERSION_MAJOR 1)