Add ability works with links in Relation ship.

[5ghz]

When sever return JSON object with only 'links object' without 'data: resource linkage'. This patch add ability to retrieve data from links object. Relay to #40

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This change is 

[coveralls]

Coverage increased (+0.5%) to 91.717% when pulling d94724e on 5ghz:master into 49303e1 on socialwifi:master.

[coveralls]

Coverage increased (+0.5%) to 91.717% when pulling d94724e on 5ghz:master into 49303e1 on socialwifi:master.

[coveralls]

Coverage increased (+0.5%) to 91.717% when pulling d94724e on 5ghz:master into 49303e1 on socialwifi:master.