.travis.yml: Test under both Linux and OS X

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

.travis.yml

@@ -1,5 +1,9 @@
 language: c
 
+os:
+  - linux
+  - osx
+
 addons:
     apt:
         packages:
@@ -7,4 +11,13 @@ addons:
         - autopoint
         - xmlto
 
+before_install:
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew update; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install asciidoc; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install gettext; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install xmlto; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew link --force gettext; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then sudo mkdir /etc/xml; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then sudo ln -s /usr/local/etc/xml/catalog /etc/xml/catalog; fi
+
 script: ./autogen.sh && ./configure && make && make check