Update to version 0.4.1 (pyro-ppl#2020)

Bump up Pyro version to 0.4.0 (pyro-ppl#2008)

* Bump up version to 0.4.0

* update torchvision

Bump Pyro version to 0.3.4 (pyro-ppl#1959)

Bump version to 0.3.3 (pyro-ppl#1847)

Bump to version 0.3.2 (pyro-ppl#1835)

Bump to version 0.3.1 (pyro-ppl#1750)

Update setup and README to use PyTorch 1.0 (pyro-ppl#1655)

Bump to version 0.2.1 (pyro-ppl#1156)

bump version to 0.2.0 (pyro-ppl#1094)

Move tests/fakes.py into pyro/distributions/testing (pyro-ppl#674)