Drop warning if region is not us-east-1 in mock

Previously if `Fog.mock!` were used with some other region and
the bucket already existed, a warning message, `Your region <region>
does not match the default region 'us-east-1'".

We were seeing a lot of these warnings in our test suite. As far as I
can tell, there's no reason why some other region can't be used, so
drop this.

Author: stanhu

lib/fog/aws/requests/storage/put_bucket.rb

@@ -61,10 +61,6 @@ def put_bucket(bucket_name, options = {})
           end
           if !self.data[:buckets][bucket_name]
             self.data[:buckets][bucket_name] = bucket
-          elsif self.region != 'us-east-1'
-            response.status = 409
-            Fog::Logger.warning "Your region '#{self.region}' does not match the default region 'us-east-1'"
-            raise(Excon::Errors.status_error({:expects => 201}, response))
           end
           response
         end