Add FullName field to Person model

FullName read-only property of Person model object is combined from
FirstName and LastName. It exists in code only and not persisted to DB.
This fileld is very easy to play with and verify the results in tests.

Changed:
 - Person model class;
 - Unit tests.
Update webservice tests for Person.FullName

Check FullName of vet instead of FirstName.
Add UI test to check pet owner in owners table

Add step to Owners test to look for Carlos Estaban in Owners table.
Merge pull request #7 from kevstigneev/fb-fullname

Add FullName field to Person model