Add GitLab CI

Add GitLab CI configuration. The CI should support the same matrix testing as our other shared Django libraries. (Multiple Python versions, etc.)

changed milestone to %Sprint 66

changed the description

assigned to @rjw57

changed the description

added workflowIn Progress label

mentioned in commit 1352e5c6

mentioned in merge request !5 (merged)

added workflowReview Required label and removed workflowIn Progress label

closed via merge request !5 (merged)

mentioned in commit e2479e40

closed via commit 1352e5c6

removed workflowReview Required label