ADD: added new version of protobuf

libs/protobuf/kokoro/linux/pull_request_in_docker.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This is the script that runs inside Docker, once the image has been built,
+# to execute all tests for the "pull request" project.
+
+WORKSPACE_BASE=`pwd`
+MY_DIR="$(dirname "$0")"
+TEST_SCRIPT=./tests.sh
+BUILD_DIR=/tmp/protobuf
+
+set -e  # exit immediately on error
+set -x  # display all commands
+
+# The protobuf repository is mounted into our Docker image, but read-only.
+# We clone into a directory inside Docker (this is faster than cp).
+rm -rf $BUILD_DIR
+mkdir -p $BUILD_DIR
+cd $BUILD_DIR
+git clone /var/local/kokoro/protobuf
+cd protobuf
+
+# Initialize any submodules:
+git submodule update --init --recursive
+
+$TEST_SCRIPT $TEST_SET