Add licenses to local build script

Author: chaitanyaphalak

docker/build.sh

@@ -13,4 +13,7 @@ cp pkg/fluent-plugin-kubernetes-metrics-*.gem docker
 
 # Build Docker Image
 FLUENTD_HEC_GEM_VERSION=`cat docker/FLUENTD_HEC_GEM_VERSION`
+echo "Copying licenses to be included in the docker image..."
+mkdir -p docker/licenses
+cp -rp LICENSE docker/licenses/
 docker build --build-arg VERSION=$FLUENTD_HEC_GEM_VERSION --no-cache -t splunk/k8s-metrics:$TAG ./docker