SE-589 Fix encode utf-8 values in instance models

Recreated from #374

This PR fix an issue when OCIM is being created with special caracteres in instance name Example: Faculdade de São Paulo

JIRA tickets: SE-589

Merge deadline: "None"

Testing instructions:

1. Clone this branch of OCIM
2. Execute vagrant up and vagrant ssh command
3. Execute make test.unit
4. Should execute without problem

Author notes and concerns:

1. Currently looking for test in OCIM (@symbolist I will help in next week)
2. I added a new assert at tests

Reviewers

• @symbolist