accessing array indexes from a method call is not supported by PHP 5.3.3 which is what the FRMT server is running.
accessing the method/properties of an anonymous object is not allowed in PHP 5.3.3. This was causing errors.
Changed the PHP requirement to be lower.
Merge pull request #2 from Flubit/dereference-incompatibility-fix

accessing array indexes from a method call is not supported by PHP 5.3.3...
Merge branch 'master' of https://github.com/Flubit/merchant-api-client into product-filter