Add Programmatic API

[sjones6]

This migration package looks great (and kudos for the 100% test coverage!).

Would you consider adding a programmatic API? For instance, something like the following:

const Migrate = require('migrate-mongo');
const migrationConfig = require('path/to/config.js');
const migrator = new Migrate(migrationConfig);

migrator.up().then(/* etc */)
migrator.down().then(/* etc */)

[seppevs]

Nice suggestion! I will look into this when I find the time. PR's are welcome as well.

[seppevs]

Landed in 4.1.0 🎉

[sjones6]

@seppevs Awesome! Thanks!