Update README.md

Merge pull request aws-beam#57 from jkakar/aws-0.4.0

Changes for version 0.4.0.

Bump version to 0.3.0.

Bump version to 0.2.0.

Bump version to v0.1.0.

Merge branch 'master' of github.com:jkakar/aws-elixir

Bump version in README and mix.exs.

Bump version.

Bump version to 0.0.9.

Bump version for v0.0.8.