[phase-5]added category model and modified term model

app/models/glossary_category.rb

@@ -0,0 +1,3 @@
+class GlossaryCategory < ActiveRecord::Base
+  has_many :terms, class_name: 'GlossaryTerm', foreign_key: 'category_id'
+end

app/models/glossary_term.rb

@@ -1,2 +1,3 @@
 class GlossaryTerm < ActiveRecord::Base
+  belongs_to :category, class_name: 'GlossaryCategory', foreign_key: 'category_id'
 end

db/migrate/002_create_glossary_categories.rb

@@ -0,0 +1,7 @@
+class CreateGlossaryCategories < ActiveRecord::Migration[5.1]
+  def change
+    create_table :glossary_categories do |t|
+      t.string :name
+    end
+  end
+end

db/migrate/003_add_category_to_glossary_terms.rb

@@ -0,0 +1,5 @@
+class AddCategoryToGlossaryTerms < ActiveRecord::Migration[5.1]
+  def change
+    add_reference :glossary_terms, :category, foreign_key: true
+  end
+end

test/unit/glossary_category_test.rb

@@ -0,0 +1,9 @@
+require File.expand_path('../../test_helper', __FILE__)
+
+class GlossaryCategoryTest < ActiveSupport::TestCase
+
+  # Replace this with your real tests.
+  def test_truth
+    assert true
+  end
+end