add group relationship to user and green specs

app/models/user.rb

@@ -1,6 +1,9 @@
 class User < ActiveRecord::Base
   has_secure_password
 
+  has_many :user_group_memberships
+  has_many :groups, through: :user_group_memberships
+
   validates :first_name, presence: true
   validates :last_name,  presence: true
   validates :email,      presence: true

spec/factories/user.rb

@@ -6,6 +6,7 @@
     city Faker::Address.city
     state Faker::Address.state
     country Faker::Address.country
+    password "helloworld"
     email_confirmed true
   end
 

spec/models/group_spec.rb

@@ -38,11 +38,11 @@
     end
 
     it "has many user_group_memberships" do
-      expect { described_class.user_group_memberships.count }.to eq(2)
+      expect(group.user_group_memberships.count).to eq(2)
     end
 
     it "has many users through user_group_memberships" do
-      expect(described_class.users.count).to eq(2)
+      expect(group.users.count).to eq(2)
     end
   end
 end