[phase-6]add relation to project to term and category models

app/models/glossary_category.rb

@@ -1,3 +1,4 @@
 class GlossaryCategory < ActiveRecord::Base
   has_many :terms, class_name: 'GlossaryTerm', foreign_key: 'category_id'
+  belongs_to :project
 end

app/models/glossary_term.rb

@@ -1,3 +1,4 @@
 class GlossaryTerm < ActiveRecord::Base
   belongs_to :category, class_name: 'GlossaryCategory', foreign_key: 'category_id'
+  belongs_to :project
 end

db/migrate/004_add_project_to_terms_and_categories.rb

@@ -0,0 +1,6 @@
+class AddProjectToTermsAndCategories < ActiveRecord::Migration[5.1]
+  def change
+    add_reference :glossary_terms, :project, foreign_key: true
+    add_reference :glossary_categories, :project, foreign_key: true
+  end
+end