Update README.md
Merge branch 'working'
Merge remote-tracking branch 'upstream/master'
Add evaluation and take out debugging statements
Merge branch 'working'

Conflicts:
	grace/lang/typecheckR.rkt
Merge branch 'master' into working
Remove evaluation
Fix error for objects in bindings
Finish up typechecking methods, check the last statement in a method body
Add typechecking for if-then-else statements
Only allow boolean expressions in if statement checks