Updated GroupCategory functionality with Groups

• Updated:
- GroupCategory functionality with Groups

db/migrate/20200908210102_remove_group_categories_id_from_group.rb

@@ -0,0 +1,5 @@
+class RemoveGroupCategoriesIdFromGroup < ActiveRecord::Migration[5.2]
+  def change
+    safety_assured { remove_column :groups, :group_categories_id }
+  end
+end

db/migrate/20200908210103_add_foreign_key_to_group_for_group_category.rb

@@ -0,0 +1,6 @@
+class AddForeignKeyToGroupForGroupCategory < ActiveRecord::Migration[5.2]
+  def change
+    add_column :groups, :group_category_id, :integer
+    add_foreign_key :groups, :group_categories, on_delete: :nullify, validate: false
+  end
+end

db/migrate/20200908210104_validate_add_foreign_key_to_group_for_group_category.rb

@@ -0,0 +1,5 @@
+class ValidateAddForeignKeyToGroupForGroupCategory < ActiveRecord::Migration[5.2]
+  def change
+    validate_foreign_key :groups, :group_categories
+  end
+end