Use tag for versioning and sbt-git for easy integration with sbt

[rubenfiszel]

git tags represent specific point in time of a branch. Releases should be tag of the master branch (instead of using a branch release)

Versions in build.sbt should be in sync with tags.

The solution ? sbt-git that sync with the tags automatically

[rubenfiszel]

Once we hit our first stable release (that pass a sufficient number of test) we should release our first v0.3 tag!

[rubenfiszel]

A nice rule for sbt-git is to add -SNAPSHOT to project version and toggle isSnapshot for every commit that doesn't fit exactly a tag. That is exactly our need.