Spelling
add sbt-pgp and sbt-release plugins
enable sbt-release
Setting version to 0.1
Setting version to 0.2-SNAPSHOT
README
support for mutable specifications

Fixes #3
bump dependencies
Setting version to 0.2
Setting version to 0.3-SNAPSHOT
Scala 2.11.0
update README
Setting version to 0.2.1
Setting version to 0.3-SNAPSHOT
update README