bin/verify-exercises-in-docker script

[keiravillekode]

This script, adapted from generic-track, is useful for testing exercises against a test runner image.

[keiravillekode]

One exercise fails:

Verifying gigasecond exercise...
gigasecond: testing...
gigasecond: done
{
	"version": 2,
	"status": "error",
	"tests": [],
	"message": "Test.hx:3: characters 8-25 : Type not found : datetime.DateTime\nTest.hx:11: characters 18-26 : Type not found : DateTime\nTest.hx:12: characters 20-28 : Type not found : DateTime\nGigasecond.hx:1: characters 8-25 : Type not found : datetime.DateTime\nGigasecond.hx:3: characters 31-39 : Type not found : DateTime\nTest.hx:7: lines 7-46 : ... Defined in this class\nTest.hx:18: characters 18-26 : Type not found : DateTime\nTest.hx:19: characters 20-28 : Type not found : DateTime\nTest.hx:21: characters 5-15 : Module Gigasecond does not define type Gigasecond\nTest.hx:25: characters 18-26 : Type not found : DateTime\nTest.hx:26: characters 20-28 : Type not found : DateTime\nTest.hx:28: characters 5-15 : Module Gigasecond does not define type Gigasecond\nTest.hx:32: characters 18-26 : Type not found : DateTime\nTest.hx:33: characters 20-28 : Type not found : DateTime\nTest.hx:35: characters 5-15 : Module Gigasecond does not define type Gigasecond\nTest.hx:39: characters 18-26 : Type not found : DateTime\nTest.hx:40: characters 20-28 : Type not found : DateTime\nTest.hx:42: characters 5-15 : Module Gigasecond does not define type Gigasecond"
}

All the other exercises succeed.