Update to 0.017

Upstream changes:
0.017          2021-04-16      T. R. Wyant
    All uses of the postderef argument to new() now warn.

0.016          2021-03-26      T. R. Wyant
    Add rt.cpan.org back to bug reporting methods. Long live RT!

    Get prerequisites up to snuff, and add xt/author/prereq.t to ensure
    they stay that way.

    Refactor authortest into three, so I do not have to generate stub
    files to test without optional modules.

0.015          2021-02-05      T. R. Wyant
    Handle <<\EOD and <<~\EOD, which are equivalent to <<'EOD' and
    <<~'EOD', respectively.

    Recognize indented here documents. Thanks to Olaf Alders (oalders)
    for alerting me to this omission.

0.014          2021-01-14      T. R. Wyant
    Add Travis CI testing.

    Use GitHub as bug tracker. R.I.P. rt.cpan.org.

(wen)