Added sponsor email validation

OSRA-123#Code-Review
Create provinces fixture
Refactor province_spec
Refactor addresses & partners factories to use provinces fixture
Refactor orphan_importer_spec; delete provinces factory. All specs green
Refactor all features
Create sponsor_types fixture
Refactor sponsors factory, sponsor_type_spec & sponsor_spec; delete sponsor_types factory
Refactor features. All green. OSRA-220 #Code-Review
Merge pull request #134 from motasem-salem/validate_email

OSRA-123 #Resolved
Create Agent model, factory & spec; OSRA-233
Set up agent-sponsor association; OSRA-234
copyedit front page
Merge pull request #138 from theB264/copyedit_front_page

copyedit front page
Merge pull request #135 from NikitaAvvakumov/province_fixture

Province fixture
Merge pull request #136 from NikitaAvvakumov/sponsor_type_fixture

Sponsor Type fixture
Write failing specs; OSRA-209 #In-Progress
Write failing spec for updating sponsor affiliation & type
Make affiliation-related attributes readonly in sponsor
Introduce sponsor validation for affiliation attributes & refactor sponsor_spec