updated dgl dependency

[guillaume-be]

Issue #, if available: https://github.com/awslabs/dgl-ke/issues/256

Description of changes:

• Update the Graph structure to leverage the (deprecated) dgl._deprecate.graph.DGLGraph. Effectively uses a deprecated class in a recent version of DGL instead of using a deprecated version of the DGL package.
• Updates dgl dependency from ==0.4.3post2 to >~0.5, <~0.9, allowing sharing a recent DGL package installation with other applications, and allowing use of Python binaries for 3.9+

Integration tests have been updated and are running on my local environment. I have re-ran training on FB15k to validate that the results are as expected, here are the output of the script:

TransE_l1_FB15k_0 Test average MRR : 0.6469265924837936 Test average MR : 47.05067630478577 Test average HITS@1 : 0.5219143065125019 Test average HITS@3 : 0.7437236545851602 Test average HITS@10 : 0.8403954563152816

TransE_l2_FB15k_0 Test average MRR : 0.6384227261417044 Test average MR : 39.936754075603936 Test average HITS@1 : 0.5046384858898614 Test average HITS@3 : 0.743528973608031 Test average HITS@10 : 0.8484196983291293

DistMult_FB15k_0 Test average MRR : 0.6508987590985638 Test average MR : 55.72816610519544 Test average HITS@1 : 0.5342046012425725 Test average HITS@3 : 0.7367828545309881 Test average HITS@10 : 0.84824194613262

ComplEx_FB15k_0 Test average MRR : 0.7075530292466494 Test average MR : 60.922652401347534 Test average HITS@1 : 0.6077686174264868 Test average HITS@3 : 0.7832100353811515 Test average HITS@10 : 0.8677015794552319

The full training logs are available on this gist

[guillaume-be]

Hello @zheng-da @classicsong - could you please let me know if there is anything further that needs to be addressed?

[guillaume-be]

Fixes https://github.com/awslabs/dgl-ke/issues/267, https://github.com/awslabs/dgl-ke/issues/256,