travis arm64: switch to zesty

Let's use Ubuntu 17.04 "Zesty" for ARM-64 bit CI.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

scripts/build/Dockerfile.aarch64.hdr

-FROM aarch64/ubuntu:trusty
+FROM arm64v8/ubuntu:zesty
 
 COPY scripts/build/qemu-user-static/usr/bin/qemu-aarch64-static /usr/bin/qemu-aarch64-static

scripts/build/Makefile

@@ -40,7 +40,7 @@ $(foreach t,$(TARGETS),$(eval $(call CLANG_DEP,$(t))))
 %-clang:	DB_CC=--build-arg CC=clang-3.8
 %-clang:	DB_ENV=--build-arg ENV1=CCACHE_CPP2
 alpine-clang:	DB_CC=--build-arg CC=clang
-aarch64-clang:	DB_CC=--build-arg CC=clang-3.6
+aarch64-clang:	DB_CC=--build-arg CC=clang
 .PHONY: $(TARGETS_CLANG)
 
 clean: