fix(bump-my-version): improve bump-my-version config verification (solves #106)

mentioned in commit 4d592d0b

mentioned in merge request Orange-OpenSource/k8s-tz/tools/glauth-config-generator!346 (merged)

mentioned in merge request Orange-OpenSource/k8s-tz/tools/kube-score-lint!372 (merged)

mentioned in merge request Orange-OpenSource/lfn/ci_cd/chained-ci-py!360 (merged)

mentioned in merge request euri10/yatg!96

mentioned in merge request Orange-OpenSource/k8s-tz/tools/glauth-config-generator!401 (merged)

mentioned in merge request Orange-OpenSource/k8s-tz/tools/kube-score-lint!409 (merged)

mentioned in merge request Orange-OpenSource/lfn/ci_cd/chained-ci-py!381 (merged)

mentioned in merge request Orange-OpenSource/k8s-tz/tools/gitlab-tokens-manager!11 (merged)