Add no-exception and no-rtti to build matrix
diff --git a/ci/travis.sh b/ci/travis.sh
index 2dda68f..9ff3bad 100755
--- a/ci/travis.sh
+++ b/ci/travis.sh
@@ -24,11 +24,19 @@
 
 env | sort
 
+# Set default values to OFF for these variables if not specified.
+: "${NO_EXCEPTION:=OFF}"
+: "${NO_RTTI:=OFF}"
+: "${COMPILER_IS_GNUCXX:=OFF}"
+
 mkdir build || true
 cd build
 cmake -Dgtest_build_samples=ON \
       -Dgtest_build_tests=ON \
       -Dgmock_build_tests=ON \
+      -Dcxx_no_exception=$NO_EXCEPTION \
+      -Dcxx_no_rtti=$NO_RTTI \
+      -DCMAKE_COMPILER_IS_GNUCXX=$COMPILER_IS_GNUCXX \
       -DCMAKE_CXX_FLAGS=$CXX_FLAGS \
       -DCMAKE_BUILD_TYPE=$BUILD_TYPE \
       ..