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
Diagram
Merge pull request #24 from Bionexo/vs-diagram

Diagram
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'
Merge branch '1.0' into ws-new-db-modeling

Conflicts:
	app/models/area.rb
	app/models/position.rb
	app/models/profile.rb
	app/models/skill.rb
	app/models/skill_level.rb
	app/models/specialization.rb
	db/schema.rb