ci: Make docker quiet

Author: tesuji

ci/build-run-docker.sh

@@ -22,7 +22,7 @@ travis_fold end "fetch.image.${TARGET}"
 if [ -f "ci/docker/$DOCKER/Dockerfile" ]; then
   travis_fold start "build.Dockerfile.${DOCKER}"
   travis_time_start
-  travis_do_cmd docker build -t "$DOCKER" "ci/docker/$DOCKER/"
+  travis_do_cmd docker build --quiet -t "$DOCKER" "ci/docker/$DOCKER/"
   travis_time_finish
   travis_fold end "build.Dockerfile.${DOCKER}"
 fi

ci/fetch-rust-docker.sh

@@ -41,6 +41,6 @@ if [ -z "$(docker images -q "rust-$TARGET")" ]; then
   set +e
   travis_retry curl -y 30 -Y 10 --connect-timeout 30 -f -L -C - -o "$cache" "$url"
   set -e
-  docker load -i "$cache"
+  docker load --quiet -i "$cache"
   docker tag "$digest" "rust-$TARGET"
 fi