try adding multi-os builds

.travis.yml

@@ -1,12 +1,17 @@
 language: cpp
-before_install:
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq libboost-all-dev
-script: cmake . && make
+os:
+- linux
+- osx
 compiler:
 - clang
 - gcc
-
+before_install:
+- if [ "$TRAVIS_OS_NAME" = "linux" ]; then sudo apt-get update -qq && sudo apt-get install libboost-dev-all; fi
+- if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew update && brew install boost; fi
+script: cmake . && make
+matrix:
+  allow_failures:
+  - os: osx
 env:
   global:
   - secure: "O+BGqz4ugoVIJbQTh0dJjKRrsSVzkCYSe0WpRzEWK3l8Mw7hqX300g81TxRwTzN2zfUsROMzaeGaXWfGzYakgW59K1WIioaczxtv2MzzUQTbqzJPa+qQoP9bk/b2wJ5jcOL965/rudRju4UiIwuIgzDAMN3nAfIEJgV/2zANLIg="