crate doc comment is incorrect and references function that doesn't exist

[wfraser]

See:

rustls-native-certs/src/lib.rs

Lines 4 to 11 in f5b6e5b

	//! It provides the following functions:
	//! * A higher level function [load_native_certs](fn.build_native_certs.html)
	//! which returns a `rustls::RootCertStore` pre-filled from the native
	//! certificate store. It is only available if the `rustls` feature is
	//! enabled.
	//! * A lower level function [build_native_certs](fn.build_native_certs.html)
	//! that lets callers pass their own certificate parsing logic. It is
	//! available to all users.

build_native_certs is gone, and load_native_certs doesn't return a RootCertStore any more.

Consider replacing this with the snippet in the example:

    let mut roots = rustls::RootCertStore::empty();
    for cert in rustls_native_certs::load_native_certs().expect("could not load platform certs") {
        roots
            .add(&rustls::Certificate(cert.0))
            .unwrap();
    }

It was not very obvious to me how to upgrade this crate without digging into the examples to figure out how to turn a vec of certificates into a RootCertStore.

[djc]

Oops, thanks for the bug report. Do the changes proposed in #38 make things clearer? If you have any suggestions about how to further improve things, that would be much appreciated.

[wfraser]

Yeah, that looks great. Thanks!