Add master 'ci.sh' about pin-project HOT 1 CLOSED

@Aaron1011
Personally, I prefer to open PR as a draft and let CI do those checks but I agree that this is helpful. However, it takes a lot of time to do exactly the same checks that CI does. (FYI: This is a script to run exactly the same checks done by CI.)

So I am thinking of adding the simplified version.

As far as I know, this can detect most cases with the following exceptions.

• If you already have nightly rust, clippy, and rustfmt installed and it is not up to date. (this can happen even with the full version of ci.sh)
• If you add a new dependency that does not support -Zminimal-versions.
• If you use a feature that is not supported by Rust 1.33.

In addition, the following cases will cause an error.

• If clippy is not available on the latest nightly.
• If rustfmt is not available on your default toolchain. (this can happen even with the full version of ci.sh)

Any thoughts?

from pin-project.