include missing migrations

[bugzpodder]

I've been using a fork of this package (see #140) to use --include-missing flag. https://github.com/elijahcarrel/goose/
This is probably same as #63 (comment)

With regards to
https://github.com/pressly/goose#hybrid-versioning
I'd like to clarify why this doesn't fit my needs:

1. --include-missing is not used in production, so the --fix flag that renames migration does not apply.
2. --including-missing flag is used in development only. To use the example from sequential numbering with postgres or redshift schemas #63 (comment)

joe branch:

migrations/2018-09-15-12:00:00_joe_1.sql
migrations/2018-10-10-12:00:00_joe_2.sql

alice branch:

migrations/2018-10-01-12:00:00_alice_1.sql
migrations/2018-10-18-12:00:00_alice_2.sql

Joe's branch get merged into master branch first:
master branch:

+migrations/2018-09-15-12:00:00_joe_1.sql
+migrations/2018-10-10-12:00:00_joe_2.sql

Alice rebased her branch to master and has:

migrations/2018-09-15-12:00:00_joe_1.sql
migrations/2018-10-01-12:00:00_alice_1.sql
migrations/2018-10-10-12:00:00_joe_2.sql
migrations/2018-10-18-12:00:00_alice_2.sql

Alice tries to run goose up on her own dev instance, but cannot apply joe's migrations without --including-missing flag.

While the down flag might be used to undo Alice's migrations,

• It is tedious to do this every time
• Not every migration has a down, or it may take too much effort (think a super complicated migration)

[bugzpodder]

owner is unresponsive so assuming no interest, closing.

[elijahcarrel]

Out of order migrations have been added in #280