GitLab

* Switch to cmake for build
* Hide symbols

Signed-off-by: Eli Uriegas <eliuriegas@fb.com>

* Use env var for switching SoX build and default to not

* Update README

* Fix packaging/CI script

* Clean up extension build mechanism and extension location

* Add back the switch to depend on external sox

* Remove print

* Fix

* Add windows binary jobs

* Make wheel package platform-specific and python-version-specific

* Refactor version suffix so conda packages don't get suffixes.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>

* typofix
Signed-off-by: Edward Z. Yang <ezyang@fb.com>

Also bugfixes and updates to the packaging scripts.

Signed-off-by: Edward Z. Yang <ezyang@fb.com>

* New entry points are packaging/build_wheel.sh and packaging/build_conda.sh. The only mandatory environment variable you have to set is PYTHON_VERSION
* CircleCI configuration uses 2.1-style parametrized builds to let you toggle python version, etc. as you do builds. We create a separate job per build configuration for maximum parallelism
* build_tools/packaging got moved to packaging, to be in-line with directory structure in torchvision
* The build_conda.sh and build_wheel.sh delegate most of the heavy lifting to pkg_helpers.bash, which defines a number of bash functions for performing common operations. The intent is that I'll copy-paste this file between other domain API projects.
* TORCHAUDIO_ prefix removed from envvars, so that I can more easily share packaging scripts between projects
* BUILD_VERSION is completely gone; just change the version number if you need to rebuild
* No more logic for cloning and checking out a fresh copy of torchaudio