adds candidate recruitment project label field

completes #93

app/models/candidate.rb

@@ -14,6 +14,7 @@ class Candidate < ApplicationRecord
   validates :recruiter_id, presence: true
   validates :name, presence: true
   validates :experience, presence: true
+  validates :project, presence: true
   validates :email, uniqueness: true, presence: true, email_format: true
   validates :test_hash, uniqueness: true, presence: true