Add script to bump versions. (#256)

* Add script to bump versions.

* Include docker directory in search

build/bump_version.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Copyright 2019 The Kanister 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.
+
+set -o errexit
+set -o nounset
+set -o pipefail
+set -o xtrace
+
+
+usage() {
+    echo ./build/bump_version.sh previous_version release_version
+    exit 1
+}
+
+main() {
+    local prev=${1:?"$(usage)"}
+    local next=${2:?"$(usage)"}
+    local -a pkgs=(docker/ scripts/ examples/ pkg/ helm/ docs/)
+    grep -E "${prev}" -r  "${pkgs[@]}" | cut -d ':' -f 1 | uniq | xargs sed -ri "s/${prev}/${next//./\\.}/g"
+}
+
+main $@
+