Bump xcode to 8.3

Author: martin-frbg

.travis.yml

@@ -149,11 +149,11 @@ matrix:
 
     - &test-macos
       os: osx
-      osx_image: xcode8
+      osx_image: xcode8.3
       before_script:
         - COMMON_FLAGS="DYNAMIC_ARCH=1 TARGET=NEHALEM NUM_THREADS=32"
         - brew update
-        - travis_wait 30 brew install gcc # for gfortran
+        - brew install gcc # for gfortran
       script:
         - travis_wait 45 make QUIET_MAKE=1 $COMMON_FLAGS $BTYPE
       env: