Migration of data on IM updates

[douradofrazer]

When changes are made to the IM tables, it should be updated without affecting existing data. We will use alter scrips and maintain versions for the changes so that we could also do a possible rollback.

Suggested tools:

1. Flywaydb
2. Liquibase

[raisoman]

Note that even thoughh we use SQL to formulate the IM, we are not running a system. The priority is to keep the IM as readable as possible, so versioning will be out of scope for the foreseeable future.