Why I switch Timeshape back to sbt as the build system?

[RomanIakovlev]

I have found it difficult to setup the proper publishing process for Timeshape when using Maven as build system. It probably mostly stems from the non-standard approach to project setup of Timeshape, but also definitely from my limited experience with Maven.

I'd still want to use Maven eventually, but for now I switch back to sbt (see #75), because there's a new version of data released and it's in the best interest of Timeshape users to get the fresh data. Hence I hope the switch to sbt is temporary, and I'll eventually have more time to setup Maven properly.

cc #72

If there's interest, I could write a bit about reasons of switching to Maven.