Merge pull request #845 from YosysHQ/clifford/travisnomacos

Disable macOS builds in Travis

.travis.yml

@@ -132,11 +132,11 @@ matrix:
       env:
         - MATRIX_EVAL="CONFIG=clang && CC=clang-5.0 && CXX=clang++-5.0"
 
-    # Latest clang on Mac OS X
-    - os: osx
-      osx_image: xcode9.4
-      env:
-        - MATRIX_EVAL="CONFIG=clang && CC=clang && CXX=clang++"
+#   # Latest clang on Mac OS X
+#   - os: osx
+#     osx_image: xcode9.4
+#     env:
+#       - MATRIX_EVAL="CONFIG=clang && CC=clang && CXX=clang++"
 
 before_install:
   - ./.travis/setup.sh