Disable 32-bit builds in Travis

Author: reuk

.travis.yml

@@ -174,7 +174,7 @@ jobs:
         - BUILD_SYSTEM=cmake
         - CCACHE_CPP2=yes
       install:
-        - cmake -H. -Bbuild '-DCMAKE_BUILD_TYPE=Release' '-DCMAKE_CXX_FLAGS_RELEASE=-O3' '-DCMAKE_CXX_FLAGS=-Wall -Wpedantic -Werror' '-DCMAKE_OSX_ARCHITECTURES=i386;x86_64'
+        - cmake -H. -Bbuild '-DCMAKE_BUILD_TYPE=Release' '-DCMAKE_CXX_FLAGS_RELEASE=-O3' '-DCMAKE_CXX_FLAGS=-Wall -Wpedantic -Werror' '-DCMAKE_OSX_ARCHITECTURES=x86_64'
         - cmake --build build -- -j4
       script: (cd build; ctest -V -L CORE)