What?

cargo-shuttle uses the library part of cargo-generate for cloning repos in cargo shuttle init.
Get rid of cargo-generate and re-implement its core functionality.

Why?

• Reduce dependency tree weight from cargo-generate, which has more features than we need.
  • It also panics sometimes
  • It is not written to be used as a library
• Possibly get rid of openssl/native-tls dependency

Requirements

• All documented features and options of the cargo shuttle init command should remain the same and work the same way. (https://github.com/shuttle-hq/shuttle-examples#readme)
• The solution should mimic cargo-generate, which includes, but not limited to:
  • Create a temp dir with tempdir
  • Parse the --from parameter and determine if the arg is a repo or path:
    • gh:aaa/bbb => clone from GitHub user aaa repo bbb, same for gl: and bb:
    • aaa/bbb => same as above
    • aaa & aaa/bbb/ccc etc => could be seen as relative paths, but should error, to not get confused with the previous bullet
    • ./aaa => from local path aaa/
    • ../../aaa/bbb => also local path
    • /aaa/bbb => local absolute path
    • C:/aaa/bbb => local absolute path (windows)
  • Clone/Copy from the source into the temp dir
  • Take only the subfolder param (if provided) and copy all of those files into target folder
  • Do a git init if relevant (same way it does now)
  • Do the final modifications with set_crate_name , edit_shuttle_toml, create_gitignore_file. (basically no change)

Bonus requirements (optional)

• Get rid of openssl/native-tls dependency. NOTE: We only need to support cloning over HTTP, which should hopefully simplify this a bit. Investigate the suitable crate for this (gix?)
• Update unit/integration tests to cover any missing parts of the init API
• Allow passing args or syntax for specifying a branch/tag/commit to clone from. A --rev arg??