Increasing to scala 2.11.3 and sbt 0.13.5
Some new tests and object for the cake pattern
Merge branch 'master' into solution

Conflicts:
	src/main/scala/section4/Section4.scala
Adding differentiated tests
Merge branch 'master' into solution
Adding absence import
First solutions for section4
Merge branch 'solution' of https://github.com/DarkToast/scala-workshop.git into solution
Solution for section7: implicits