Create goal models in project manager

[JASchilz]

For example, a goal might be "implement feature Y".

Requires a User submodel:

• Create a GitHub specific user submodel #21

Projects model

• Create project model #22

Should have a name/title, description, FK into users, FK into projects, size, and completion date, and a unique, deterministic ID that can be used to update it from its primary record (eg: if the issue is updated in GitHub then the code in the project manager that imports issues from Github must be able to identify which of its issues has been updated and modify that issue)