Added OSX target to Travis

.travis.yml

@@ -7,6 +7,7 @@ branches:
 
 os:
   - linux
+  - osx
 
 addons:
   apt:
@@ -16,6 +17,10 @@ addons:
       - libc++-dev
       - ninja-build
 
+before_install:
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew update       ; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install ninja; fi
+
 env:
   - CMAKE_BUILD_TYPE=DEBUG
   - CMAKE_BUILD_TYPE=RELEASE