Travis CI : added ARM compilation tests

Makefile

@@ -98,5 +98,11 @@ clangtest: clean
 gpptest: clean
 	$(MAKE) all CC=g++ CFLAGS="-O3 -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror"
 
+armtest: clean
+	cd $(ZSTDDIR); $(MAKE) -e all CC=arm-linux-gnueabi-gcc MOREFLAGS="-Werror"
+	cd $(PRGDIR); $(MAKE) -e CC=arm-linux-gnueabi-gcc CPPFLAGS="-Werror"
+
+sanitize: clean
+	$(MAKE) test CC=clang CPPFLAGS="-g -fsanitize=undefined" FUZZER_TIME="-T1mn" NB_LOOPS=-i1
 
 endif