Add values to default fields to prevent 500 error when migrate from MySQL to Postgres

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Re-annotate models

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix default value for project model

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Modify project default values

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'ensure_default_fields' into 'master'

Add values to default fields to prevent 500 error when migrate from MySQL to Postgres