Travis: Added OSX, use default compilers, moved cmds into own scripts

.travis-build.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+set -e
+
+#if OS is linux or is not set
+if [ "$TRAVIS_OS_NAME" = linux -o -z "$TRAVIS_OS_NAME" ]; then 
+    mkdir build && cd build
+    cmake .. 
+    make -j4
+elif [ "$TRAVIS_OS_NAME" = osx ]; then
+    mkdir build && cd build
+    cmake .. -GXcode
+    xcodebuild
+fi