Support pytorch==1.1.0

[HiromuHota]

Is your feature request related to a problem? Please describe.

Fonduer depends on Emmental and Snorkel.
They have a conflict on the pytorch version: Snorkel requires torch<1.2.0,>=1.1.0, while Emmental requires torch>=1.3.1, <2.0.0.

Describe the solution you'd like

While waiting for Snorkel to support Pytorch > 1.1.0, I'd like Emmental to support pytorch 1.1.0 if it is relatively easy.

Describe alternatives you've considered

Upgrade Snorkel to support Pytorch > 1.1.0.
A few issues have been filed for Snorkel to ask them to support Pytorch > 1.1.0.
snorkel-team/snorkel#1541 (on Jan 31, 2020)
snorkel-team/snorkel#1558 (on Mar 19, 2020)

Additional context

[HiromuHota]

These are the differences of pytorch between 1.1.0 and higher that are used by Emmental.

• optim.AdamW has been added at v1.2.0 of PyTorch.
• optim.lr_scheduler.OneCycleLR has been added at v1.3.0.
• optim.lr_scheduler.CosineAnnealingLR has been renamed from CosineAnnealingLr at v1.2.0.
• Tensor.any() returns True if any elements in the tensor are non-zero as of v1.1.0 and only supports torch.uint8 dtype, while it does so if any elements in the tensor are True as of v1.2.0 and higher.

[HiromuHota]

Given that snorkel-team/snorkel#1565 is merged, this issue can be closed.