Add this to your Cargo.toml:

[dependencies]
bit-vec = "0.6"

and this to your crate root:

extern crate bit_vec;

If you want serde support, include the feature like this:

[dependencies]
bit-vec = { version = "0.6", features = ["serde"] }

If you want to use bit-vec in a program that has #![no_std], just drop default features:

[dependencies]
bit-vec = { version = "0.6", default-features = false }