pin pytorch version to 1.x.x in setup.py and in meta.yaml.

[erip]

Fixes #897

Description: Pins the version to >=1.0, <2 in conda recipe and in setup.py.

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

Shouldn't we run simple tests on those pytorch version: 1.0, 1.1, 1.2 etc ?

[erip]

Yes, probably so. Do we want to only run integration tests?

[vfdev-5]

I do not want to load more our CI with complete matrix of Python and Pytorch versions.
Something in the middle can be to check for a single Python version (e.g. 3.6), all previous pytorch version (1.0, 1.1, 1.2, 1.3, 1.4) and run them cron-based once per week or so (another github action). No smoke or distrib tests there only pytest -vvv tests/

[vfdev-5]

But maybe we can leave it for another PR...

[erip]

I added an action to run on Sundays - let me know what you think, @vfdev-5

[vfdev-5]

Looks good ! Thanks @erip !