Update version string to 1.4.

official/testing/docker_test.sh

@@ -35,9 +35,9 @@ EXIT=0
 export WORKSPACE=${PWD}
 
 if [ "$PYTHON_VERSION" = "PYTHON3" ]; then
-  DOCKER_IMG_NAME="tensorflow/tensorflow:1.3.0-py3"
+  DOCKER_IMG_NAME="tensorflow/tensorflow:1.4.0-py3"
 else
-  DOCKER_IMG_NAME="tensorflow/tensorflow:1.3.0"
+  DOCKER_IMG_NAME="tensorflow/tensorflow:1.4.0"
   if [ "$PYTHON_VERSION" != "PYTHON2" ]; then
     echo "WARNING: Python version was not specified. Using Python2 by default."
     sleep 5
@@ -74,4 +74,4 @@ ${DOCKER_BINARY} rmi \
 git clean -dfx
 
 # Return exit status
-exit ${EXIT}
\ No newline at end of file
+exit ${EXIT}