finished exercises in Chapter 2 - Getting started
finished List execises for Chapter 3
finished Tree execises for Chapter 3
solved Either, Option and Stream exercises
State exercises up to 6.7
finished Chapter 6 - State exercises
Merge branch 'master' of https://github.com/fpinscala/fpinscala

Conflicts:
	exercises/src/main/scala/fpinscala/gettingstarted/GettingStarted.scala