Added cassandra upgrade docker image and kubernetes yaml file

+#
+# Copyright © 2016-2018 The Thingsboard Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+FROM openjdk:8-jre
+
+ADD upgrade.sh /upgrade.sh
+ADD thingsboard.deb /thingsboard.deb
+
+RUN apt-get update \
+        && apt-get install -y nmap \
+        && chmod +x /upgrade.sh

+VERSION=2.0.3
+PROJECT=thingsboard
+APP=cassandra-upgrade
+
+build:
+	cp ../../application/target/thingsboard.deb .
+	docker build --pull -t ${PROJECT}/${APP}:${VERSION} -t ${PROJECT}/${APP}:latest .
+	rm thingsboard.deb
+
+push: build
+	docker push ${PROJECT}/${APP}:${VERSION}
+	docker push ${PROJECT}/${APP}:latest

+#!/bin/bash
+#
+# Copyright © 2016-2018 The Thingsboard Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+
+dpkg -i /thingsboard.deb
+
+until nmap $CASSANDRA_HOST -p $CASSANDRA_PORT | grep "$CASSANDRA_PORT/tcp open"
+do
+  echo "Wait for cassandra db to start..."
+  sleep 10
+done
+
+echo "Upgrading 'Thingsboard' schema..."
+/usr/share/thingsboard/bin/install/upgrade.sh --fromVersion=$UPGRADE_FROM_VERSION

+#
+# Copyright © 2016-2018 The Thingsboard Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+apiVersion: v1
+kind: Pod
+metadata:
+  name: cassandra-upgrade
+spec:
+  containers:
+  - name: cassandra-upgrade
+    imagePullPolicy: Always
+    image: thingsboard/cassandra-upgrade:2.0.3
+    env:
+    - name: ADD_DEMO_DATA
+      value: "true"
+    - name : CASSANDRA_HOST
+      value: "cassandra-headless"
+    - name : CASSANDRA_PORT
+      value: "9042"
+    - name : DATABASE_TYPE
+      value: "cassandra"
+    - name : CASSANDRA_URL
+      value: "cassandra-headless:9042"
+    - name : UPGRADE_FROM_VERSION
+      value: "1.4.0"
+    command:
+    - sh
+    - -c
+    - /upgrade.sh
+  restartPolicy: Never