Manage customer project types

[enriquezrene]

As part of #87 and #89, we have implemented all the required functionality to manage customers' information. Now, we need to add the required code to manage project types customers have.

A project type is comprised of:

• Name (required)
• Description (optional)

Considering these fields, we need to implement the required code to create, edit and delete activity types.

Acceptance Criteria

• All the required code to manage activity types has at least 80% code coverage
• User can manage project types