Merge pull request rust-lang#981 from ehuss/release-0.3.1

Release 0.3.1

Merge pull request rust-lang#956 from ehuss/rel-0.3.0

Release 0.3.0

(cargo-release) v version 0.2.2

(cargo-release) v version 0.2.1

(cargo-release) v version 0.2.0

(cargo-release) v version 0.1.10

(cargo-release) v version 0.1.9

(cargo-release) v version 0.1.8

(cargo-release) v version 0.1.7