[travis] add osx build check (#3164)

.travis.yml

@@ -166,4 +166,7 @@ matrix:
     - env: BUILD_TARGET="toranj-test-framework" VERBOSE=1 TORANJ_POSIX_APP_RCP_MODEL=1
       os: linux
       compiler: gcc
-      python: "2.7"
+      python: "2.7"
+    - env: BUILD_TARGET="osx" VERBOSE=1
+      os: osx
+      language: generic

.travis/before_install.sh

@@ -162,14 +162,3 @@ cd /tmp || die
     }
 
 }
-
-[ $TRAVIS_OS_NAME != osx ] || {
-    sudo easy_install pexpect || die
-
-    [ $BUILD_TARGET != cc2538 ] || {
-        wget https://launchpad.net/gcc-arm-embedded/4.9/4.9-2015-q3-update/+download/gcc-arm-none-eabi-4_9-2015q3-20150921-mac.tar.bz2 || die
-        tar xjf gcc-arm-none-eabi-4_9-2015q3-20150921-mac.tar.bz2 || die
-        export PATH=/tmp/gcc-arm-none-eabi-4_9-2015q3/bin:$PATH || die
-        arm-none-eabi-gcc --version || die
-    }
-}

.travis/script.sh

@@ -525,3 +525,15 @@ python --version || die
 [ $BUILD_TARGET != toranj-test-framework ] || {
     ./tests/toranj/start.sh
 }
+
+[ $BUILD_TARGET != osx ] || {
+    git checkout -- . || die
+    git clean -xfd || die
+    ./bootstrap || die
+    make -f examples/Makefile-posix || die
+
+    git checkout -- . || die
+    git clean -xfd || die
+    ./bootstrap || die
+    make -f src/posix/Makefile-posix || die
+}