Allow using clippy with either beta or nightly
Allow using clippy with either beta or nightly

Not 100% sure this will _always_ work, but it works currently.

aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust