Creating resource doesn't handle UnknownResponse error correctly

[niborg]

Was trying to create a resource, e.g.,

api.contacts.new(contact_params).save

Was receiving this error:

NoMethodError: undefined method `to_i' for false:FalseClass
Did you mean?  to_s
	from /app/vendor/bundle/ruby/2.3.0/gems/clio_client-0.1.9/lib/clio_client/resource.rb:164:in `convert_attribute'
	from /app/vendor/bundle/ruby/2.3.0/gems/clio_client-0.1.9/lib/clio_client/resource.rb:55:in `block (2 levels) in set_attributes'
	from /app/vendor/bundle/ruby/2.3.0/gems/clio_client-0.1.9/lib/clio_client/resource.rb:113:in `save'
	from (irb):28

Turns out, there was an error in our code where we were accidentally populating the 'id' field of one of the contact's phone numbers, so Clio was returning a 'conflict' error which ClioClient initially manifests with a Net::HTTPConflict error. This error is rescued in http.rb and ClioClient::UnknownResponse is thrown in its place.

Then crudable.rb rescues UnknownResponse and returns false.

Where it appears to go wrong is in resource.rb:

def save
  if self.id.nil?
    saved_item = api.create(self.to_params)
    self.id = saved_item && saved_item.id # Trying to assign 'false' to the 'id' attribute
    self
  else
    api.update(self.id, self.to_params)
    self
  end
end

I can make a PR with some guidance on the expected behavior.