FIX: Incorrect route for updating username.

spec/support/integration_helpers.rb

@@ -0,0 +1,9 @@
+module IntegrationHelpers
+  def sign_in(user)
+    password = 'somecomplicatedpassword'
+    user.update!(password: password)
+    Fabricate(:email_token, confirmed: true, user: user)
+    post "/session.json", { login: user.username, password: password }
+    expect(response).to be_success
+  end
+end