macOS build disabled for now

.travis.yml

@@ -5,12 +5,8 @@ rust: nightly
 matrix:
   include:
     - os: linux
-    - os: osx
-      osx_image: xcode9.3
-      before_install:
-        - rustup self uninstall
-        - curl https://sh.rustup.rs -sSf | sh -y
-        - rustup install nightly
+#    - os: osx
+#      osx_image: xcode9.3
 
 script:
   - cargo build --release