Add release script

Script release.sh added to simplify the core release process.

Committed-by: Rene Pfeuffer <rene.pfeuffer@cloudogu.com>

release.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+git fetch
+git checkout -f origin/develop
+git clean -fd
+git checkout -B develop
+
+echo These are the current changes
+cat ./gradle/changelog/*.yaml
+echo Next version number:
+read new_version
+
+./gradlew :updateChangelog --release=${new_version}
+
+git diff 
+
+echo Proceed? Press Ctrl+c to abort
+read x 
+
+git rm -rf gradle/changelog 
+git checkout -b release/${new_version}
+git add CHANGELOG.md 
+git commit -m "Adjust changelog for release ${new_version}"
+git push origin release/${new_version}
+