private String makeJdbcUrl(final String dbName) {
        String url = ConnectionConfig.DEFAULT_JDBC_DRIVER_URL;
        final Matcher matcher = DB_NAME_IN_URL_PATTERN.matcher(url);
        return matcher.replaceFirst(dbName);
    }
Do a hacky string replace as if we modify the map representation of the yaml
and write it back to a string we lose any commented stuff and it changes loads
of lines when we only really want to change a few.
stroom-test-common/src/main/java/stroom/test/common/util/db/SetupDevEnv.java