maco os travis

.travis.yml

-language: python
-sudo: required
-dist: trusty
-matrix:
+jobs:
   include:
-    - python: 3.5
-    - python: 3.6
-addons:
-  apt:
-    sources:
-      - ubuntu-toolchain-r-test
-    packages:
-      - gcc-4.9
-      - g++-4.9
-before_install:
-  - export CC="gcc-4.9"
-  - export CXX="g++-4.9"
+    - os: linux
+      language: python
+      python: 3.7
+      addons:
+        apt:
+          sources:
+            - ubuntu-toolchain-r-test
+          packages:
+            - gcc-5
+            - g++-5
+      env:
+        - CC=gcc-5
+        - CXX=g++-5
+    - os: osx
+      language: sh
+      before_cache:
+        - brew cleanup
+      cache:
+        directories:
+          - $HOME/Library/Caches/Homebrew
+          - /usr/local/Homebrew
+      addons:
+        homebrew:
+          packages: python3
+      before_install:
+        - python3 -m pip install --upgrade virtualenv
+        - virtualenv -p python3 --system-site-packages "$HOME/venv"
+        - source "$HOME/venv/bin/activate"
+      env:
+        - CC=clang
+        - CXX=clang++
 install:
   - pip install numpy
   - pip install --pre torch torchvision -f https://download.pytorch.org/whl/nightly/cpu/torch_nightly.html