Linting for changelog and version

Linting jobs for changelog and chart version (as well as minor clean up) per discussion with @runyontr.

scripts/lint_changelog.sh

+#!/usr/bin/env bash
+
+# diff the file silently, while still printing errors
+git diff --exit-code origin/${CI_DEFAULT_BRANCH}:${CHANGELOG_FILE} ${CHANGELOG_FILE} >/dev/null
+
+# exit code of 0 indicates non changed file
+if [ $? -eq 0 ]; then
+  echo "No changes were detected in ${CHANGELOG_FILE}, please update this file"
+  exit 1
+fi
+
+# exit code other than 0 and 1 is an error
+# IE - different file names between branches
+# check for this and fail accordingly
+if [ $? -ne 1 ]; then
+  echo "Error: An unknown error has occurred while linting ${CHANGELOG_FILE}"
+  exit 1
+fi
+
+# default to success
+exit 0
\ No newline at end of file