v7.2.0: Simpler GPU install and bug fixes

✨ New features and improvements

• Ditch thinc_gpu_ops for simpler GPU install.
• Improve GPU support and PyTorch wrapper.

🔴 Bug fixes

• Fix issue #47: Fix ExtractWindow nW>=2.
• Fix issue #51: Ditch thinc_gpu_ops for simpler GPU install.
• Fix issue #88: Fix Quora URL in datasets.
• Fix issue #115: Fix compilation on cygwin.

👥 Contributors

Thanks to @rupsaijna and @KoichiYasuoka for the pull requests!