v0.3.0

This release pins the minimum rustc version to 1.15!

* serde was updated to 0.9
* serde_json was updated to 0.9
* uuid was updated to 0.4
* serde_derive was added (0.9) for the custom derive functionality.

The codebase was reduced:

    11 files changed, 126 insertions(+), 492 deletions(-)

since v0.2.2.