Squash Migrations

[rasjonell-zz]

Is your feature request related to a problem? Please describe.
After a while mostly all projects end up with a pile of migrations and release after release you want to maintain the schema and only add new migrations.

Describe the solution you'd like
User should be able to squash a specified number of migrations into a single migration file.

[rasjonell-zz]

Since Arango is a schemaless, we can just get the collection definitions, generate a squash file that creates all those collections with their corresponding definitions and hide all the previous migrations.