Bump ar_transaction changes to 1.0 and loosen version constraint.

@arthurnn and @fbogsany for review

Bump ar_transaction_changes due the private methods create_record and update_record being prefixed with an underscore in active record 4 stable branches.  Instead, the public run_callbacks method is now overridden to avoid these problems (https://github.com/dylanahsmith/ar_transaction_changes/commit/69c295832fce6fd234fea218770c733805bc0d4f).

I also loosened the constrain to allow minor and bug fix releases.  I released ar_transaction_changes v1.0.0 so will follow semantic versioning to avoid breaking the API.