v1.3.1
Issues/null links (#56)
Fixes non-standards links nodes such as the following breaking the deserialiser with an exception
```
"links": {
"self": "/v1/products?page[size]=10&page[number]=1",
"first": "/v1/products?page[size]=10&page[number]=1",
"last": "/v1/products?page[size]=10&page[number]=2",
"prev": null,
"next": "/v1/products?page[size]=10&page[number]=2"
}
```
* Bump to version 1.3.1