Require authentication for most endpoints (#29)

Reviewed-on: #29

test/test_helper.rb

@@ -10,4 +10,8 @@ class ActiveSupport::TestCase
   fixtures :all
 
   # Add more helper methods to be used by all tests here...
+  def login(email, password = "secret")
+    post sessions_url, params: { session: { email: email, password: password } }
+    assert session[:current_user_id].present?
+  end
 end