add MTTM method in Paper ‘A Multi-Type Transferable Method for Missing Link Prediction in Heterogeneous Social Networks’

[xihairanfeng]

We add the implementation of MTTM method from the paper A Multi-Type Transferable Method for Missing Link Prediction in Heterogeneous Social Networks. MTTM effectively learns transferable feature representations to improve the prediction performance of missing links in heterogeneous social networks.