Fix bug with docker compatibility

ArgsEscaped according to Docker docs should only be set in Windows
environments: https://docs.docker.com/engine/api/v1.30/

It was causing integration test to fail with following message:
```
FAIL: TestRun/test_Dockerfile_test_metadata (8.48s)
           "Diff": {
             "Adds": [
               "ArgsEscaped: true"
             ],
             "Dels": [
               "ArgsEscaped: false"
             ]
```

However docker 18.xx returns ArgsEscaped: true
whereas docker 19.xx returns ArgsEscaped: false
Hence this patch also adds the docker version check to the integration
to ignore ArgsEscaped being different when 18.xx is used.

integration-test.sh

@@ -18,6 +18,8 @@ set -ex
 GCS_BUCKET="${GCS_BUCKET:-gs://kaniko-test-bucket}"
 IMAGE_REPO="${IMAGE_REPO:-gcr.io/kaniko-test}"
 
+docker version
+
 # Sets up a kokoro (Google internal integration testing tool) environment
 if [ -f "$KOKORO_GFILE_DIR"/common.sh ]; then
     echo "Installing dependencies..."