travis-ci: Extend build matrix, disable email notifications

We'll be testing both gcc and clang builds on Linux. As for now,
Travis CI only supports clang for OSX - so exclude gcc currently.

Signed-off-by: Bernhard Nortmann <bernhard.nortmann@web.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index d16577b..0df62d6 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-CC = gcc
+CC ?= gcc
 CFLAGS = -g -O0 -Wall -Wextra
 CFLAGS += -std=c99 $(DEFINES)
 CFLAGS += -Iinclude/