downgrade blueprints dep
write release notes
Setting version to 0.4.0:

- introduce `java.util.stream.Stream` as a substitute for `List`
- add new arities covering the one / exactly one distinction, using `java.util.Optional`
- improve documentation
Setting version to '0.5.0-SNAPSHOT'
add a property method to element index
Merge branch 'feature/get/property/from/index'
Merge branch 'master' into feature/add/sequence/option/stream
add a option to stream method