Please tag releases and track changes

[beruic]

I am currently in doubt whether I should upgrade from 1.3.1 to 1.4.0 because I have no way of assesing if there are any breaking changes.
I releases were at lease tagged, i could look at a diff of the two versions. Optimally there would also be releases here on GitHub stating the changes.

[cozmo]

We follow semantic versioning, so there should be no breaking changes between those two versions, as it's a minor not a major change.

Adding tags to correspond with npm versions is a good idea.