Squashed commit of the following:

commit aed8416
Author: Benjamin Foote <git@bnf.net>
Date:   Thu Jun 25 13:23:31 2020 -0700

    vouch#281 gofmt, minor edits

commit c38b05d
Author: Benjamin Foote <git@bnf.net>
Date:   Thu Jun 25 13:23:15 2020 -0700

    vouch#281 compile regex once, use cfg.Branding

commit d9cb3f6
Author: Benjamin Foote <git@bnf.net>
Date:   Thu Jun 25 13:20:01 2020 -0700

    error on empty URL

commit 4adbaad
Author: Ben Artin <ben@artins.org>
Date:   Thu Jun 25 12:57:06 2020 -0400

    Fixed handling of multiple vouch params in login request

commit dfc6cb3
Author: Ben Artin <ben@artins.org>
Date:   Thu Jun 25 12:59:24 2020 -0400

    Allow ‘error’ param

commit e50e1aa
Author: Ben Artin <ben@artins.org>
Date:   Thu Jun 25 12:29:16 2020 -0400

    Clarified README unit tests

commit dabee5c
Author: Ben Artin <ben@artins.org>
Date:   Thu Jun 25 12:28:32 2020 -0400

    Log about url normalization

commit c1b37a7
Author: Benjamin Foote <git@bnf.net>
Date:   Wed Jun 24 12:17:02 2020 -0700

    vouch#281 add tests for README 302 syntax

commit ddbea36
Author: Ben Artin <ben@artins.org>
Date:   Tue Jun 23 17:23:25 2020 -0400

    Allow semicolon as param separator in URL

    https://www.w3.org/TR/html401/appendix/notes.html#h-B.2.2

commit f27d4b1
Author: Ben Artin <ben@artins.org>
Date:   Tue Jun 23 16:59:31 2020 -0400

    Added tests for the case of vouch param before url param

commit 5b4c71d
Author: Ben Artin <ben@artins.org>
Date:   Tue Jun 23 16:59:05 2020 -0400

    Unambiguous test name

commit 881dfc2
Author: Ben Artin <ben@artins.org>
Date:   Sat Jun 20 04:21:01 2020 -0400

    More robust parsing of url param to login; see vouch#281

Merge branch 'bug/278_dontcache401'

vouch#277 log OAuth config

vouch#274 move debug logging of config post LogLevel

add docker alpine build and run

upgrade to go 1.14

1.14 includes testing.Cleanup() which is used in the env var testing

Merge branch 'fix/bad_file'

Revert "print warning for deprecated config items"

This reverts commit ea2ebab.

style and spacing

cleanup debug logging