Following links in a 301 response for a sparql query

[Catgolin]

Current behavior

The following code throws a Http\Exception stating that the HTTP request for SPARQL query failed, and doesn't return any information about the response:

$sparql = new EasyRdf\Sparql\Client('http://uri/returning/a/redirecting/response');
$sparql->query('...');

Expected behavior

When there is a 301/302/303/307/308 HTTP response to the query and the Location header is set, we could automatically try again the query with the new Location instead of imediatly throwing the error. We could easily keep in sight the previous automatic redirections in order to make sure there is no circular redirections and throw the Exception it happends.

It would be useful to return the response headers in the thrown exception to better identify the error and take the appropriate steps (this second option could also be useful when we have other HTTP errors such as 401 where the body of the response doesn't always carry as much information).

[madbob]

Mostly handled by PR #379, as the PSR HTTP client provided by implementor can be configured with desidered behaviour (handle as many redirects as required, or just fail when a redirect is found).