Initial commit: Create scripts for the newly added users_roles table (InnoDB) to Workbench schema. Unfortunately this propagates to the crop schema as well (MyISAM) due to the same users table and related common entities used in crop schema too!

Issue: BMS-62
Reviewer: RebeccaB
Upgrade scripts for the new table users_role.

Issue: BMS-62
Reviewer: Darla
Adding .gitignore.
Merging branch 'BMS-33-authentication-authorisation' into 'master' so that further development/testing work can be done as part of mainstream.

Issue: BMS-33
Reviewer : RebeccaB