adding skill_level model for manage skill definitions
seeding skill levels
organizing code and associate skill with many skill_levels
fixing association between position and profile. position belongs_to profile
adding comments to make model more understandable
seeding positions with profiles and specializations
fixing association name skill_levels
Merge pull request #22 from Bionexo/ws-skill-levels

Níveis de competência
Merge pull request #23 from Bionexo/ws-position-seed

Seeding cargos
Merge remote-tracking branch 'origin/ws-skill-description'
Merge remote-tracking branch 'origin/ws-skill-levels'