v1.2.0

Better download compatibility

by @VirtualPirate in #48

• Eliminates the dependency on native curl command
• Deprecates curl and curl_to_file functions; they will be removed in the next major version
• The new reqwest dependency can be opted out of by disabling the download_ffmpeg feature
• For more advanced download functionality like async streaming or progress updates, it's encouraged to opt out and roll your own
• Future work: also replace the dependency on native tar command in the unpack_ffmpeg function (PRs welcome!)

Full Changelog: v1.1.2...v1.2.0