Bump to 1.6.0 (pyro-ppl#2777)

* Use torch==1.8.0 and torchvision==0.9.0

* Change version

* Update tutorial versions

Bump to version 1.5.2 (pyro-ppl#2755)

Bump to version 1.5.1 (pyro-ppl#2698)

* Bump to version 1.5.1

* Bump torch version in docs, add instructions

Bump version to 1.5.0 (pyro-ppl#2671)

* Add script to update version

* Bump version_prefix

* Fix script

* Bump version

Bump to version 1.4.0 (pyro-ppl#2565)

Bump to version 1.3.1 (pyro-ppl#2400)

Bump version to 1.3.0 (pyro-ppl#2352)

* Include neutra example in tutorials

* Fix link

* Bump version to 1.3.0

Release patch to fix mcmc parallel chains using multiprocessing (pyro…

…-ppl#2275)

Bump version to 1.2.0 (pyro-ppl#2267)

Bump to version 1.1.0 (pyro-ppl#2215)