add script to prep release branch

prep_repo_release.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+set -ueE
+
+function update ( ) {
+  upgrade=$1
+  npm version $upgrade || exit 255
+}
+
+RELEASE_NOTES="Release.md"
+TYPE=${1-'patch'}
+echo "First update"
+
+npm ls . || echo -n ""
+NEW_TAG=$(update ${TYPE})
+echo "Updating to $NEW_TAG"
+# npm commits a new package json on your behalf with a new tag pointed at it
+git reset --hard HEAD~1
+git tag -d $NEW_TAG || echo "warning ${NEW_TAG} not present"
+BRANCH_NAME="release/${NEW_TAG}"
+git checkout -b ${BRANCH_NAME}
+npm ls . || echo -n ""
+cat /dev/null > ${RELEASE_NOTES}
+git changelog -t ${NEW_TAG} ${RELEASE_NOTES}
+echo "saving release notes"
+git add ${RELEASE_NOTES}
+git commit -vm "Release notes for ${NEW_TAG}"
+
+echo "Final update"
+update ${TYPE}
+echo "New version $NEW_TAG"
+echo "Branch ${BRANCH_NAME}"
+npm ls . || echo -n ""
+