🐞🔨 Authentication: Don't explode when OTP or OTP secrets are nil

- #1809

There's a couple things happening, one of which is if an
`AuthenticationMethod` does not have a One Time Password Secret, it
can't actually do the verification.

So i've added a check to make sure it returns false in cases when the
OTP secret has not been set yet; as well as when a nil OTP is provided.

app/models/authentication_method.rb

@@ -37,6 +37,7 @@ def contact_location=(contact_location)
   end
 
   def verify?(one_time_password)
+    return false if one_time_password.blank? || one_time_password_secret.blank?
     totp.verify(one_time_password).present?
   end
 

spec/models/authentication_method_spec.rb

@@ -41,6 +41,15 @@
 
       expect(authentication_method).not_to be_verify(one_time_password)
     end
+
+    it "is false when the OTP is nil" do
+      expect(authentication_method).not_to be_verify(nil)
+    end
+
+    it "is false when the OTPS is nil" do
+      authentication_method.one_time_password_secret = nil
+      expect(authentication_method).not_to be_verify("an otp")
+    end
   end
 
   describe "#send_one_time_password!(space)" do