Makefile: fix 'clean' and add 'distclean'

* fix 'clean' to remove .eunit (not .test)
* add 'distclean' to also remove deps/

Makefile

@@ -7,7 +7,10 @@ all:
 	./bootstrap
 
 clean:
-	@rm -rf rebar ebin/*.beam inttest/rt.work rt.work .test
+	@rm -rf rebar ebin/*.beam inttest/rt.work rt.work .eunit
+
+distclean: clean
+	@rm -rf deps
 
 debug:
 	@./bootstrap debug