GitLab

* Changes hydrogen mass for benchmarks

* Adds amber case for hydrogen mass
Co-authored-by: David Clark <daclark@nvidia.com>

* Top level Python module is now "openmm"

* Updated module names in examples

* Updated module names in documentation

* Updated module in CI scripts

* Added deprecation warning

* Add benchmarks from Amber20 benchmark suite to standard benchmark script

* Add ensemble option; don't change hydrogen mass in amber input files

* Download and extract .tar.gz using pure python code, no wget/tar dependencies

* Rename amber tests

* Added HMR to make ApoA1 benchmark more stable

* Removed debugging code