migrate dies when parsing files with duplicate timestamps

[nickpalmer]

Describe the Bug When running migrations that were created with the same timestamp migrate will crash.

Steps to Reproduce Steps to reproduce the behavior:

1. Write two migrations with the same timestamp

20220311025833_first.down.sql 
20220311025833_first.up.sql
20220311025833_second.down.sql
20220311025833_second.up.sql

2. Run migrate with these files

Expected Behavior The migrations should run in alphabetical order without error

Migrate Version dev

Loaded Source Drivers file

Loaded Database Drivers postgresql, stub, cockroach, cockroachdb, crdb-postgres, postgres

Go Version go version go1.17.6 darwin/arm64

[DUWAPP01]

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